Section

[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.105]

[Page 223-242]

TITLE 49--TRANSPORTATION

OF TRANSPORTATION

PART 571_FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents

Subpart B_Federal Motor Vehicle Safety Standards

Sec. 571.105 Standard No. 105; Hydraulic and electric brake systems.

S1. Scope. This standard specifies requirements for hydraulic and
electric service brake systems, and associated parking brake systems.
S2. Purpose. The purpose of this standard is to insure safe braking
performance under normal and emergency conditions.
S3. Application. This standard applies to multi-purpose passenger
vehicles, trucks, and buses with a GVWR greater than 3,500 kilograms
(7,716 pounds) that are equipped with hydraulic or electric brake
systems.
S4. Definitions.
Antilock brake system or ABS means a portion of a service brake
system that automatically controls the degree of rotational wheel slip
during braking by:
(1) Sensing the rate of angular rotation of the wheels;
(2) Transmitting signals regarding the rate of wheel angular
rotation to one or more controlling devices which interpret those
signals and generate responsive controlling output signals; and
(3) Transmitting those controlling signals to one or more modulators
which adjust brake actuating forces in response to those signals.
Backup system means a portion of a service brake system, such as a
pump, that automatically supplies energy, in the event of a primary
brake power source failure.
Brake power assist unit means a device installed in a hydraulic
brake system that reduces the operator effort required to actuate the
system, and that if inoperative does not prevent the operator from
braking the vehicle by a continued application of muscular force on the
service brake control.
Brake power unit means a device installed in a brake system that
provides the energy required to actuate the brakes, either directly or
indirectly through an auxiliary device, with the operator action
consisting only of modulating the energy application level.
Directly Controlled Wheel means a wheel for which the degree of
rotational wheel slip is sensed, either at that wheel or on the axle
shaft for that wheel and corresponding signals are transmitted to one or
more modulators that adjust the brake actuating forces at that wheel.
Each modulator may also adjust the brake actuating forces at other
wheels that are on the same axle or in the same axle set in response to
the same signal or signals.
Electric vehicle or EV means a motor vehicle that is powered by an
electric motor drawing current from rechargeable storage batteries, fuel
cells, or other portable sources of electrical current, and which may
include a non-electrical source of power designed to charge batteries
and components thereof.
Electrically-actuated service brakes means service brakes that
utilize electrical energy to actuate the foundation brakes.
Full brake application means a brake application in which the force
on the brake pedal reaches 150 pounds within 0.3 seconds from the point
of application of force to the brake control.
Hydraulic brake system means a system that uses hydraulic fluid as a
medium for transmitting force from a service brake control to the
service brake, and that may incorporate a brake power assist unit, or a
brake power unit.
Indirectly Controlled Wheel means a wheel at which the degree of
rotational wheel slip is not sensed, but at which the modulator of an
antilock braking system adjusts its brake actuating forces in response
to signals from one or more sensed wheels.
Initial brake temperature means the average temperature of the
service brakes on the hottest axle of the vehicle 0.2 mi before any
brake application.
Lightly loaded vehicle weight means:

[[Page 224]]

(a) For vehicles with a GVWR of 10,000 lbs. or less, unloaded
vehicle weight plus 400 lbs. (including driver and instrumentation);
(b) For vehicles with a GVWR greater than 10,000 lbs., unloaded
vehicle weight plus 500 lbs. (including driver and instrumentation).
Maximum drive-through speed means the highest possible constant
speed at which the vehicle can be driven through 200 feet of a 500-foot
radius curve arc without leaving the 12-foot lane.
Parking mechanism means a component or subsystem of the drive train
that locks the drive train when the transmission control is placed in a
parking or other gear position and the ignition key is removed.
Peak friction coefficient or PFC means the ratio of the maximum
value of braking test wheel longitudinal force to the simultaneous
vertical force occurring prior to wheel lockup, as the braking torque is
progressively increased.
Pressure component means a brake system component that contains the
brake system fluid and controls or senses the fluid pressure.
Regenerative braking system or RBS means an electrical energy system
that is installed in an EV for recovering or dissipating kinetic energy,
and which uses the propulsion motor(s) as a retarder for partial braking
of the EV while returning electrical energy to the propulsion batteries
or dissipating electrical energy.
Skid number means the frictional resistance of a pavement measured
in accordance with American Society for Testing and Materials (ASTM)
Method E-274-70 (as revised July, 1974) at 40 mph, omitting water
delivery as specified in paragraphs 7.1 and 7.2 of that method.
Snub means the braking deceleration of a vehicle from a higher
reference speed to a lower reference speed that is greater than zero.
Spike stop means a stop resulting from the application of 200 lbs of
force on the service brake control in 0.08 s.
Split service brake system means a brake system consisting of two or
more subsystems actuated by a single control, designed so that a single
failure in any subsystem (such as a leakage-type failure of a pressure
component of a hydraulic subsystem except structural failure of a
housing that is common to two or more subsystems, or an electrical
failure in an electric subsystem) does not impair the operation of any
other subsystem.
Stopping distance means the distance traveled by a vehicle from the
point of application of force to the brake control to the point at which
the vehicle reaches a full stop.
Tandem axle means a group of two or more axles placed in close
arrangement one behind the other with the center lines of adjacent axles
not more than 72 inches apart.
Variable proportioning brake system means a system that
automatically adjusts the braking force at the axles to compensate for
vehicle static axle loading and/or dynamic weight transfer between axles
during deceleration.
Wheel lockup means 100 percent wheel slip.
S5. Requirements.
S5.1 Service brake systems. Each vehicle must be equipped with a
service brake system acting on all wheels. Wear of the service brake
must be compensated for by means of a system of automatic adjustment.
Each passenger car and each multipurpose passenger vehicle, truck, and
bus with a GVWR of 10,000 pounds or less must be capable of meeting the
requirements of S5.1.1 through S5.1.6 under the conditions prescribed in
S6, when tested according to the procedures and in the sequence set
forth in S7. Each school bus with a GVWR greater than 10,000 pounds must
be capable of meeting the requirements of S5.1.1 through S5.1.5, and
S5.1.7 under the conditions specified in S6, when tested according to
the procedures and in the sequence set forth in S7. Each multipurpose
passenger vehicle, truck and bus (other than a school bus) with a GVWR
greater than 10,000 pounds must be capable of meeting the requirements
of S5.1.1, S5.1.2, S5.1.3, and S5.1.7 under the conditions specified in
S6, when tested according to the procedures and in the sequence set
forth in S7. Except as noted in S5.1.1.2 and S5.1.1.4, if a vehicle is
incapable of attaining a speed specified in S5.1.1, S5.1.2, S5.1.3, or
S5.1.6, its service

[[Page 225]]

brakes must be capable of stopping the vehicle from the multiple of 5
mph that is 4 to 8 mph less than the speed attainable in 2 miles, within
distances that do not exceed the corresponding distances specified in
Table II. If a vehicle is incapable of attaining a speed specified in
S5.1.4 in the time or distance interval set forth, it must be tested at
the highest speed attainable in the time or distance interval specified.
S5.1.1 Stopping distance. (a) The service brakes shall be capable of
stopping each vehicle with a GVWR of less than 8,000 pounds, and each
school bus with a GVWR between 8,000 pounds and 10,000 pounds in four
effectiveness tests within the distances and from the speeds specified
in S5.1.1.1, S5.1.1.2, S5.1.1.3, and S5.1.1.4.
(b) The service brakes shall be capable of stopping each vehicle
with a GVWR of between 8,000 pounds and 10,000 pounds, other than a
school bus, in three effectiveness tests within the distances and from
the speeds specified in S5.1.1.1, S5.1.1.2, and S5.1.1.4.
(c) The service brakes shall be capable of stopping each vehicle
with a GVWR greater than 10,000 pounds in two effectiveness tests within
the distances and from the speeds specified in S5.1.1.2 and S5.1.1.3.
Each school bus with a GVWR greater than 10,000 pounds manufactured
after January 12, 1996 and before March 1, 1999 and which is equipped
with an antilock brake system may comply with paragraph S5.1.1.2 and
S5.5.1 rather than the first effectiveness test, as specified in
S5.1.1.1. Each school bus with a GVWR greater than 10,000 pounds
manufactured on or after March 1, 1999 shall be capable of meeting the
requirements of S5.1.1 through S5.1.5, under the conditions prescribed
in S6, when tested according to the procedures and in the sequence set
forth in S7.
S5.1.1.1 In the first (preburnished) effectiveness test, the vehicle
shall be capable of stopping from 30 mph and 60 mph within the
corresponding distances specified in column I of table II.
S5.1.1.2 In the second effectiveness test, each vehicle with a GVWR
of 10,000 pounds or less and each school bus with a GVWR greater than
10,000 pounds shall be capable of stopping from 30 mph and 60 mph, and
each vehicle with a GVWR greater than 10,000 pounds (other than a school
bus) shall be capable of stopping from 60 mph, within the corresponding
distances specified in Column II of Table II. If the speed attainable in
2 miles is not less than 84 mph, a passenger car or other vehicle with a
GVWR of 10,000 pounds or less shall also be capable of stopping from 80
mph within the corresponding distances specified in Column II of Table
II.
S5.1.1.3 In the third effectiveness test the vehicle shall be
capable of stopping at lightly loaded vehicle weight from 60 mph within
the corresponding distance specified in column III of table II.
S5.1.1.4 In the fourth effectiveness test, a vehicle with a GVWR of
10,000 pounds or less shall be capable of stopping from 30 and 60 mph
within the corresponding distances specified in column I of table II. If
the speed attainable in 2 miles is not less than 84 mph, a passenger
car, or other vehicle with a GVWR of 10,000 lbs., or less, shall also be
capable of stopping from 80 mph within the corresponding distance
specified in column I of table II.
If the speed attainable in 2 miles is not less than 99 mph, a
passenger car shall, in addition, be capable of stopping from the
applicable speed indicated below, within the corresponding distance
specified in column I of table II.

------------------------------------------------------------------------
Required
Speed attainable in 2 miles (mph) to stop
from (mph)
------------------------------------------------------------------------
Not less than 99 but less than 104.......................... 95
104 or more................................................. 100
------------------------------------------------------------------------

For an EV, the speed attainable in 2 miles is determined with the
propulsion batteries at a state of charge of not less than 95 percent at
the beginning of the run.
S5.1.2 Partial failure.
S5.1.2.1 In vehicles manufactured with a split service brake system,
in the event of a rupture or leakage type of failure in a single
subsystem, other than a structural failure of a housing that is common
to two or more subsystems, the remaining portion(s) of the service brake
system shall continue to operate and shall be capable of stopping a
vehicle from 60 mph within

[[Page 226]]

the corresponding distance specified in column IV of table II.
S5.1.2.2 In vehicles not manufactured with a split service brake
system, in the event of any one rupture or leakage type of failure in
any component of the service brake system the vehicle shall, by
operation of the service brake control, be capable of stopping 10 times
consecutively from 60 mph within the corresponding distance specified in
column IV of table II.
S5.1.2.3 For a vehicle manufactured with a service brake system in
which the brake signal is transmitted electrically between the brake
pedal and some or all of the foundation brakes, regardless of the means
of actuation of the foundation brakes, the vehicle shall be capable of
stopping from 60 mph within the corresponding distance specified in
Column IV of Table II with any single failure in any circuit that
electrically transmits the brake signal, and with all other systems
intact.
S5.1.2.4 For an EV manufactured with a service brake system that
incorporates RBS, the vehicle shall be capable of stopping from 60 mph
within the corresponding distance specified in Column IV of Table II
with any single failure in the RBS, and with all other systems intact.
S5.1.3 Inoperative brake power assist unit or brake power unit. A
vehicle equipped with one or more brake power assist units shall meet
the requirements of either S5.1.3.1, S5.1.3.2, or S5.1.3.4 (chosen at
the option of the manufacturer), and a vehicle equipped with one or more
brake power units shall meet the requirements of either S5.1.3.1,
S5.1.3.3, or S5.1.3.4 (chosen at the option of the manufacturer).
S5.1.3.1 The service brakes on a vehicle equipped with one or more
brake power assist units or brake power units, with one such unit
inoperative and depleted of all reserve capability, shall be capable of
stopping a vehicle from 60 mph within the corresponding distance
specified in column IV of table II.
S5.1.3.2 Brake power assist units. The service brakes on a vehicle
equipped with one or more brake power assist units, with one such unit
inoperative, shall be capable of stopping a vehicle from 60 mph:
(a) In six consecutive stops at an average deceleration for each
stop that is not lower than that specified in column I of table III,
when the inoperative unit is not initially depleted of all reserve
capability; and
(b) In a final stop, at an average deceleration that is not lower
than 7 FPSPS for passenger cars (equivalent stopping distance 554 feet)
or 6 FPSPS for vehicles other than passenger cars (equivalent stopping
distance 646 feet), as applicable, when the inoperative unit is depleted
of all reserve capacity.
S5.1.3.3 Brake power units. The service brakes of a vehicle equipped
with one or more brake power units with an accumulator-type reserve
system, with any one failure in any one unit shall be capable of
stopping the vehicle from 60 mph--
(a) In 10 consecutive stops at an average deceleration for each stop
that is not lower than that specified in column II of table III, when
the unit is not initially depleted of all reserve capability; and
(b) In a final stop, at an average deceleration that is not lower
than 7 FPSPS for passenger cars (equivalent stopping distance 554 feet)
or 6 FPSPS for vehicles other than passenger cars (equivalent stopping
distance 646 feet), as applicable, when the inoperative unit is depleted
of all reserve capacity.
S5.1.3.4 Brake power assist and brake power units. The service
brakes of a vehicle equipped with one or more brake power assist units
or brake power units with a backup system, with one brake power assist
unit or brake power unit inoperative and depleted of all reserve
capability and with only the backup system operating in the failed
subsystem, shall be capable of stopping the vehicle from 60 mph in 15
consecutive stops at an average deceleration for each stop that is not
lower than 12 fpsps (equivalent stopping distance 323 feet).
S5.1.3.5 Electric brakes. Each vehicle with electrically-actuated
service brakes (brake power unit) shall comply with the requirements of
S5.1.3.1 with any single electrical failure in the electrically-actuated
service brakes and all other systems intact.
S5.1.4 Fade and recovery. The service brakes shall be capable of
stopping

[[Page 227]]

each vehicle in two fade and recovery tests as specified below.
S5.1.4.1 The control force used for the baseline check stops or
snubs shall be not less than 10 pounds, nor more than 60 pounds, except
that the control force for a vehicle with a GVWR of 10,000 pounds or
more may be between 10 pounds and 90 pounds.
S5.1.4.2 (a) Each vehicle with GVWR of 10,000 lbs or less shall be
capable of making 5 fade stops (10 fade stops on the second test) from
60 mph at a deceleration not lower than 15 fpsps for each stop, followed
by 5 fade stops at the maximum deceleration attainable from 5 to 15
fpsps.
(b) Each vehicle with a GVWR greater than 10,000 pounds shall be
capable of making 10 fade snubs (20 fade snubs on the second test) from
40 mph to 20 mph at 10 fpsps for each snub.
S5.1.4.3 (a) Each vehicle with a GVWR of 10,000 pounds or less shall
be capable of making five recovery stops from 30 mph at 10 fpsps for
each stop, with a control force application that falls within the
following maximum and minimum limits:
(1) A maximum for the first four recovery stops of 150 pounds, and
for the fifth stop, of 20 pounds more than the average control force for
the baseline check; and
(2) A minimum of--
(A) The average control force for the baseline check minus 10
pounds, or
(B) The average control force for the baseline check times 0.60,

whichever is lower (but in no case lower than 5 pounds).
(b) Each vehicle with a GVWR of more than 10,000 pounds shall be
capable of making five recovery snubs from 40 mph to 20 mph at 10 fpsps
for each snub, with a control force application that falls within the
following maximum and minimum limits:
(1) A maximum for the first four recovery snubs of 150 pounds, and
for the fifth snub, of 20 pounds more than the average control force for
the baseline check (but in no case more than 100 pounds); and
(2) A minimum of--
(A) The average control force for the baseline check minus 10
pounds, or
(B) The average control force for the baseline check times 0.60,

whichever is lower (but in no case lower than 5 pounds).
S5.1.5 Water recovery. The service brakes shall be capable of
stopping each vehicle in a water recovery test, as specified below.
S5.1.5.1 The control force used for the baseline check stops or
snubs shall be not less than 10 pounds, nor more than 60 pounds, except
that the control force for a vehicle with a GVWR of 10,000 pounds or
more may be between 10 and 90 pounds.
S5.1.5.2(a) After being driven for 2 minutes at a speed of 5 mph in
any combination of forward and reverse directions through a trough
having a water dept of 6 inches, each vehicle with a GVWR of 10,000
pounds or less shall be capable of making five recovery stops from 30
mph at ten fpsps for each stop with a control force application that
falls within the following maximum and minimum limits:
(1) A maximum for the first four recovery stops of 150 pounds, and
for the fifth stop, of 45 pounds more than the average control force for
the baseline check (but in no case more than 90 pounds, except that the
maximum control force for the fifth stop in the case of a vehicle
manufactured before September 1, 1976, shall be not more than plus 60
pounds of the average control force for the baseline check (but in no
case more than 110 pounds).
(2) A minimum of--
(A) The average control force for the baseline check minus 10
pounds, or
(B) The average control force for the baseline check times 0.60,

whichever is lower (but in no case lower than 5 pounds).
(b) After being driven for 2 minutes at a speed of 5 mph in any
combination of forward and reverse directions through a trough having a
water depth of 6 inches, each vehicle with a GVWR of more than 10,000
pounds shall be capable of making five recovery stops from 30 mph at 10
fpsps for each stop with a control force application that falls within
the following maximum and minimum limits:
(1) A maximum for the first four recovery stops of 150 pounds, and
for the fifth stop, of 60 pounds more than the average control force for
the baseline

[[Page 228]]

check (but in no case more than 110 pounds); and
(2) A minimum of--
(A) The average control force for the baseline check minus 10
pounds, or
(B) The average control force for the baseline check times 0.60,

whichever is lower (but in no case lower than 5 pounds).
S5.1.6 Spike stops. Each vehicle with a GVWR of 10,000 lbs. or less
shall be capable of making 10 spike stops from 30 mph, followed by 6
effectiveness (check) stops from 60 mph, at least one of which shall be
within a corresponding stopping distance specified in column I of table
II.
S5.1.7 Stability and control during braking. When stopped four
consecutive times under the conditions specified in S6, each vehicle
with a GVWR greater than 10,000 pounds manufactured on or after July 1,
2005 and each vehicle with a GVWR greater than 10,000 pounds
manufactured in two or more stages on or after July 1, 2006 shall stop
from 30 mph or 75 percent of the maximum drive-through speed, whichever
is less, at least three times within the 12-foot lane, without any part
of the vehicle leaving the roadway. Stop the vehicle with the vehicle at
its lightly loaded vehicle weight, or at the manufacturer's option, at
its lightly loaded vehicle weight plus not more than an additional 1000
pounds for a roll bar structure on the vehicle.
S5.2 Parking Brake System. Each vehicle shall be manufactured with a
parking brake system of a friction type with a solely mechanical means
to retain engagement, which shall under the conditions of S6, when
tested according to the procedures specified in S7, meet the
requirements specified in S5.2.1, S5.2.2, or S5.2.3 as appropriate, with
the system engaged--
(a) In the case of a vehicle with a GVWR of 4,536 kilograms (10,000
pounds) or less, with a force applied to the control not to exceed 125
pounds for a foot-operated system and 90 pounds for a hand-operated
system; and
(b) In the case of a vehicle with a GVWR greater than 4,536
kilograms (10,000 pounds), with a force applied to the control not to
exceed 150 pounds for a foot-operated system and 125 pounds for a hand-
operated system.
S5.2.1. Except as provided in Sec. 5.2.2, the parking brake system
on a passenger car and on a school bus with a GVWR of 10,000 pounds or
less shall be capable of holding the vehicle stationary (to the limit of
traction on the braked wheels) for 5 minutes in both a forward and
reverse direction on a 30 percent grade.
S5.2.2 A vehicle of a type described in S5.2.1 at the option of the
manufacturer may meet the requirements of S5.2.2.1, S5.2.2.2, and
S5.2.2.3 instead of the requirements of S5.2.1 if:
(a) The vehicle has a transmission or transmission control which
incorporates a parking mechanism, and
(b) The parking mechanism must be engaged before the ignition key
can be removed.
S5.2.2.1 The vehicle's parking brake and parking mechanism, when
both are engaged, shall be capable of holding the vehicle stationary (to
the limit of traction of the braked wheels) for 5 minutes, in both
forward and reverse directions, on a 30 percent grade.
S5.2.2.2 The vehicle's parking brake, with the parking mechanism not
engaged, shall be capable of holding the vehicle stationary for 5
minutes, in both forward and reverse directions, on a 20 percent grade.
S5.2.2.3 With the parking mechanism engaged and the parking brake
not engaged, the parking mechanism shall not disengage or fracture in a
manner permitting vehicle movement, when the vehicle is impacted at each
end, on a level surface, by a barrier moving at 2\1/2\ mph.
S5.2.3 (a) The parking brake system on a multipurpose passenger
vehicle, truck or bus (other than a school bus) with a GVWR of 4,536
kilograms (10,000 pounds) or less shall be capable of holding the
vehicle stationary for 5 minutes, in both forward and reverse
directions, on a 20 percent grade.
(b) The parking brake system on a multipurpose passenger vehicle,
truck, or bus (including a school bus) with a GVWR greater than 4,536
kilograms (10,000 pounds) shall be capable of holding the vehicle
stationary for 5 minutes, in both forward and reverse directions, on a
20 percent grade.
S5.3 Brake system indicator lamp. Each vehicle shall have a brake
system

[[Page 229]]

indicator lamp or lamps, mounted in front of and in clear view of the
driver, which meet the requirements of S5.3.1 through S5.3.5. A vehicle
with a GVWR of 10,000 pounds or less may have a single common indicator
lamp. A vehicle with a GVWR of greater than 10,000 pounds may have an
indicator lamp which is common for gross loss of pressure, drop in the
level of brake fluid, or application of the parking brake, but shall
have a separate indicator lamp for antilock brake system malfunction.
However, the options provided in S5.3.1(a) shall not apply to a vehicle
manufactured without a split service brake system; such a vehicle shall,
to meet the requirements of S5.3.1(a), be equipped with a malfunction
indicator that activates under the conditions specified in S5.3.1(a)(4).
This warning indicator shall, instead of meeting the requirements of
S5.3.2 through S5.3.5, activate (while the vehicle remains capable of
meeting the requirements of S5.1.2.2 and the ignition switch is in the
``on'' position) a continuous or intermittent audible signal and a
flashing warning light, displaying the words ``STOP-BRAKE FAILURE'' in
block capital letters not less than one-quarter of an inch in height.
S5.3.1 An indicator lamp shall be activated when the ignition
(start) switch is in the ``on'' (``run'') position and whenever any of
the conditions (a) or (b), (c), (d), (e), (f), and (g) occur:
(a) A gross loss of pressure (such as caused by rupture of a brake
line but not by a structural failure of a housing that is common to two
or more subsystems) due to one of the following conditions (chosen at
the option of the manufacturer):
(1) Before or upon application of a differential pressure of not
more than 225 lb/in\2\ between the active and failed brake system
measured at a master cylinder outlet or a slave cylinder outlet.
(2) Before or upon application of 50 pounds of control force upon a
fully manual service brake.
(3) Before or upon application of 25 pounds of control force upon a
service brake with a brake power assist unit.
(4) When the supply pressure in a brake power unit drops to a level
not less than one-half of the normal system pressure.
(b) A drop in the level of brake fluid in any master cylinder
reservoir compartment to less than the recommended safe level specified
by the manufacturer or to one-fourth of the fluid capacity of that
reservoir compartment, whichever is greater.
(c) A malfunction that affects the generation or transmission of
response or control signals in an antilock brake system, or a total
functional electrical failure in a variable proportioning brake system.
(d) Application of the parking brake.
(e) For a vehicle with electrically-actuated service brakes, failure
of the source of electric power to the brakes, or diminution of state of
charge of the batteries to less than a level specified by the
manufacturer for the purpose of warning a driver of degraded brake
performance.
(f) For a vehicle with electric transmission of the service brake
control signal, failure of a brake control circuit.
(g) For an EV with RBS that is part of the service brake system,
failure of the RBS.
S5.3.2 (a) Except as provided in paragraph (b) of this section, all
indicator lamps shall be activated as a check of lamp function either
when the ignition (start) switch is turned to the ``on'' (run) position
when the engine is not running, or when the ignition (start) switch is
in a position between ``on'' (run) and ``start'' that is designated by
the manufacturer as a check position.
(b) The indicator lamps need not be activated when a starter
interlock is in operation.
S5.3.3 (a) Each indicator lamp activated due to a condition
specified in S5.3.1 shall remain activated as long as the malfunction
exists, whenever the ignition (start) switch is in the ``on'' (run)
position, whether or not the engine is running.
(b) For vehicles manufactured on and after September 1, 1999 with
GVWRs greater than 10,000 lbs, each message about the existence of a
malfunction, as described in S5.3.1(c), shall be stored in the antilock
brake system after the ignition switch is turned to the ``off'' position
and the indicator lamp shall

[[Page 230]]

be automatically reactivated when the ignition switch is again turned to
the ``on'' position. The indicator lamp shall also be activated as a
check of lamp function whenever the ignition is turned to the ``on''
(run) position. The indicator lamp shall be deactivated at the end of
the check of lamp function unless there is a malfunction or a message
about a malfunction that existed when the key switch was last turned to
the ``off'' position.
S5.3.4 When an indicator lamp is activated it may be steady burning
or flashing.
S5.3.5 (a) Each indicator lamp shall display word, words or
abbreviation, in accordance with the requirements of Standard No. 101
(49 CFR 571.101) and/or this section, which shall have letters not less
than \1/8\-inch high and be legible to the driver in daylight when
lighted. Words in addition to those required by Standard No. 101 and/or
this section and symbols may be provided for purposes of clarity.
(b) If a single common indicator is used, the lamp shall display the
word ``Brake''. The letters and background of a single common indicator
shall be of contrasting colors, one of which is red.
(c)(1) If separate indicators are used for one or more of the
conditions described in S5.3.1(a) through S5.3.1(g) of this standard,
the indicator display shall include the word ``Brake'' and appropriate
additional labeling, except as provided in (c)(1) (A) through (D) of
this paragraph.
(A) If a separate indicator lamp is provided for gross loss of
pressure, the words ``Brake Pressure'' shall be used for S5.3.1(a).
(B) If a separate indicator lamp is provided for low brake fluid,
the words ``Brake Fluid'' shall be used for S5.3.1(b), except for
vehicles using hydraulic system mineral oil.
(C) If a separate indicator lamp is provided for an anti-lock
system, the single word ``Antilock'' or ``Anti-lock'', or the
abbreviation ``ABS'', may be used for S5.3.1(c).
(D) If a separate indicator lamp is provided for application of the
parking brake, the single word ``Park'' may be used for S5.3.1(d).
(E) If a separate indicator is used for the regenerative brake
system, the symbol ``RBS'' may be used. RBS failure may also be
indicated by a lamp displaying the symbol ``ABS/RBS.''
(2) Except for a separate indicator lamp for an anti-lock system, a
regenerative system, or an indicator for both anti-lock and regenerative
system, the letters and background of each separate indicator lamp shall
be of contrasting colors, one of which is red. The letters and
background of a separate lamp for an anti-lock system, a regenerative
system, or a lamp displaying both an anti-lock and a regenerative system
shall be of contrasting colors, one of which is yellow.
S5.4 Reservoirs.
S5.4.1 Master cylinder reservoirs. A master cylinder shall have a
reservoir compartment for each service brake subsystem serviced by the
master cylinder. Loss of fluid from one compartment shall not result in
a complete loss of brake fluid from another compartment.
S5.4.2 Reservoir capacity. Reservoirs, whether for master cylinders
or other type systems, shall have a total minimum capacity equivalent to
the fluid displacement resulting when all the wheel cylinders or caliper
pistons serviced by the reservoirs move from a new lining, fully
retracted position (as adjusted initially to the manufacturer's
recommended setting) to a fully worn, fully applied position, as
determined in accordance with S7.18(c) of this standard. Reservoirs
shall have completely separate compartments for each subsystem except
that in reservoir systems utilizing a portion of the reservoir for a
common supply to two or more subsystems, individual partial compartments
shall each have a minimum volume of fluid equal to at least the volume
displaced by the master cylinder piston servicing the subsystem, during
a full stroke of the piston. Each brake power unit reservoir servicing
only the brake system shall have a minimum capacity equivalent to the
fluid displacement required to charge the system piston(s) or
accumulator(s) to normal operating pressure plus the displacement
resulting when

[[Page 231]]

all the wheel cylinders or caliper pistons serviced by the reservoir or
accumulator(s) move from a new lining fully retracted position (as
adjusted initially to the manufacturer's recommended setting) to a fully
worn, fully applied position.
S5.4.3 Reservoir labeling--Each vehicle equipped with hydraulic
brakes shall have a brake fluid warning statement that reads as follows,
in letters at least one-eighth of an inch high: ``WARNING, Clean filler
cap before removing. Use only ------ fluid from a sealed container.''
(Inserting the recommended type of brake fluid as specified in 49 CFR
571.116, e.g., ``DOT 3''). The lettering shall be--
(a) Permanently affixed, engraved, or embossed;
(b) Located so as to be visible by direct view, either on or within
4 inches of the brake fluid reservoir filler plug or cap; and
(c) Of a color that contrasts with its background, if it is not
engraved or embossed.
S5.5 Antilock and variable proportioning brake systems.
S5.5.1 Each vehicle with a GVWR greater than 10,000 pounds, except
for any vehicle with a speed attainable in 2 miles of not more than 33
mph, shall be equipped with an antilock brake system that directly
controls the wheels of at least one front axle and the wheels of at
least one rear axle of the vehicle. On each vehicle with a GVWR greater
than 10,000 pounds but not greater than 19,500 pounds and motor homes
with a GVWR greater than 10,000 pounds but not greater than 22,500
pounds manufactured before March 1, 2001, the antilock brake system may
also directly control the wheels of the rear drive axle by means of a
single sensor in the driveline. Wheels on other axles of the vehicle may
be indirectly controlled by the antilock brake system.
S5.5.2 In the event of any failure (structural or functional) in an
antilock or variable proportioning brake system, the vehicle shall be
capable of meeting the stopping distance requirements specified in
S5.1.2 for service brake system partial failure. For an EV that is
equipped with both ABS and RBS that is part of the service brake system,
the ABS must control the RBS.
S5.6 Brake system integrity. Each vehicle shall be capable of
completing all performance requirements of S5 without--
(a) Detachment or fracture of any component of the braking system,
such as brake springs and brake shoe or disc pad facing, other than
minor cracks that do not impair attachment of the friction facing. All
mechanical components of the braking system shall be intact and
functional. Friction facing tearout (complete detachment of lining)
shall not exceed 10 percent of the lining on any single frictional
element.
(b) Any visible brake fluid or lubricant on the friction surface of
the brake, or leakage at the master cylinder or brake power unit
reservoir cover, seal and filler openings.
S6 Test conditions. The performance requirements of S5 shall be met
under the following conditions. Where a range of conditions is
specified, the vehicle shall be capable of meeting the requirements at
all points within the range. Compliance of vehicles manufactured in two
or more stages may, at the option of the final-stage manufacturer, be
demonstrated to comply with this standard by adherence to the
instructions of the incomplete manufacturer provided with the vehicle in
accordance with Sec. 568.4(a)(7)(ii) and Sec. 568.5 of title 49 of the
Code of Federal Regulations.
S6.1 Vehicle weight.
S6.1.1 Other than tests specified at lightly loaded vehicle weight
in S7.5(a), S7.7, S7.8, and S7.9, the vehicle is loaded to its GVWR such
that the weight on each axle as measured at the tire-ground interface is
in proportion to its GAWR, except that each fuel tank is filled to any
level from 100 percent of capacity (corresponding to full GVWR) to 75
percent. However, if the weight on any axle of a vehicle at lightly
loaded vehicle weight exceeds the axle's proportional share of the gross
vehicle weight rating, the load required to reach GVWR is placed so that
the weight on that axle remains the same as a lightly loaded vehicle
weight.
S6.1.2 For applicable tests specified in S7.5(a), S7.7, S7.8, and
S7.9, vehicle weight is lightly loaded vehicle weight,

[[Page 232]]

with the added weight, except for the roll bar structure allowed for
trucks and buses with a GVWR greater than 10,000 pounds, distributed in
the front passenger seat area in passenger cars, multipurpose passenger
vehicles, and trucks, and in the area adjacent to the driver's seat in
buses.
S6.2 Electric vehicles and electric brakes.
S6.2.1 The state of charge of the propulsion batteries is determined
in accordance with SAE Recommended Practice J227a, Electric Vehicle Test
Procedure, February 1976. The applicable sections of J227a are 3.2.1
through 3.2.4, 3.3.1 through 3.3.2.2, 3.4.1 and 3.4.2, 4.2.1, 5.2,
5.2.1, and 5.3.
S6.2.2 At the beginning of the first effectiveness test specified in
S7.3, and at the beginning of each burnishing procedure, each EV's
propulsion battery is at the maximum state of charge recommended by the
manufacturer, as stated in the vehicle operator's manual or on a label
that is permanently attached to the vehicle, or, if the manufacturer has
made no recommendation, at a state of charge of not less than 95
percent. If a battery is replaced rather than recharged, the replacement
battery is to be charged and measured for state of charge in accordance
with these procedures. During each burnish procedure, each propulsion
battery is restored to the recommended state of charge or a state of
charge of not less than 95 percent after each increment of 40 burnish
stops until each burnish procedure is complete. The batteries may be
charged at a more frequent interval if, during a particular 40-stop
increment, the EV is incapable of achieving the initial burnish test
speed. During each burnish procedure, the propulsion batteries may be
charged by an external means or replaced by batteries that are charged
to the state of charge recommended by the manufacturer or a state of
charge of not less than 95 percent. For EVs having a manual control for
setting the level of regenerative braking, the manual control, at the
beginning of each burnish procedure, is set to provide maximum
regenerative braking throughout the burnish.
S6.2.3 At the beginning of each performance test in the test
sequence (S7,3, S7.5, S7.7 through S7.11, and S7.13 through S7.19 of
this standard), unless otherwise specified, each propulsion battery of
an EV is at the maximum state of charge recommended by the manufacturer,
as stated in the vehicle operator's manual or on a label that is
permanently attached to the vehicle, or, if the manufacturer has made no
recommendation, at a state of charge of not less than 95 percent. If
batteries are replaced rather than recharged, each replacement battery
shall be charged and measured for state of charge in accordance with
these procedures. No further charging of any propulsion battery occurs
during any of the performance tests in the test sequence of this
standard. If the propulsion batteries are depleted during a test
sequence such that the vehicle reaches automatic shut-down, will not
accelerate, or the low state of charge warning lamp is illuminated, the
vehicle is to be accelerated to brake test speed by auxiliary means.
S6.2.4 (a) For an EV equipped with RBS, the RBS is considered to be
part of the service brake system if it is automatically controlled by an
application of the service brake control, if there is no means provided
for the driver to disconnect or otherwise deactivate it, and if it is
activated in all transmission positions, including neutral. The RBS is
operational during all burnishes and all tests, except for the test of a
failed RBS.
(b) For an EV equipped with an RBS that is not part of the service
brake system, the RBS is operational and set to produce the maximum
regenerative braking effect during the burnishes, and is disabled during
the test procedures. If the vehicle is equipped with a neutral gear that
automatically disables the RBS, the test procedures which are designated
to be conducted in gear may be conducted in neutral.
S6.2.5 For tests conducted ``in neutral,'' the operator of an EV
with no ``neutral'' position (or other means such as a clutch for
disconnecting the drive train from the propulsion motor(s)) does not
apply any electromotive force to the propulsion motor(s). Any
electromotive force that is applied to the propulsion motor(s)
automatically remains in effect unless

[[Page 233]]

otherwise specified by the test procedure.
S6.2.6 A vehicle equipped with electrically-actuated service brakes
also performs the following test series. Conduct 10 stopping tests from
a speed of 100 kph or the maximum vehicle speed, whichever is less. At
least two of the 10 stopping distances must be less than or equal to 70
meters. The vehicle is loaded to GVWR for these tests and the
transmission is in the neutral position when the service brake control
is actuated and throughout the remainder of the test. The battery or
batteries providing power to those electrically-actuated brakes, at the
beginning of each test, shall be in a depleted state of charge for
conditions (a), (b), or (c) of this paragraph as appropriate. An
auxiliary means may be used to accelerate an EV to test speed.
(a) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries, and with automatic shut-
down capability of the propulsion motor(s), the propulsion batteries are
at not more than five percent above the EV actual automatic shut-down
critical value. The critical value is determined by measuring the state-
of-charge of each propulsion battery at the instant that automatic shut-
down occurs and averaging the states-of-charge recorded.
(b) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries, and with no automatic
shut-down capability of the propulsion motor(s), the propulsion
batteries are at an average of not more than five percent above the
actual state of charge at which the brake failure warning signal,
required by S5.3.1(e) of this standard, is illuminated.
(c) For a vehicle which has an auxiliary battery (or batteries) that
provides electrical energy to operate the electrically-actuated service
brakes, the auxiliary battery(batteries) is (are) at (at an average of)
not more than five percent above the actual state of charge at which the
brake failure warning signal, required by S5.3.1(e) of this standard, is
illuminated.
S6.3 Tire inflation pressure. Tire inflation pressure is the
pressure recommended by the vehicle manufacturer for the GVWR of the
vehicle.
S6.4 Transmission selector control. For S7.3, S7.5, S7.8, S7.15,
S7.17, S7.11.1.2, S7.11.2.2, S7.11.3.2, and as required for S7.13, the
transmission selector control is in neutral for all decelerations. For
all other tests during all decelerations, the transmission selector is
in the control position, other than overdrive, recommended by the
manufacturer for driving on a level surface at the applicable test
speed. To avoid engine stall during tests required to be run in gear a
manual transmission may be shifted to neutral (or the clutch disengaged)
when the vehicle speed decreases to 20 mph.
S6.5 Engine. Engine idle speed and ignition timing settings are
according to the manufacturer's recommendations. If the vehicle is
equipped with an adjustable engine speed governor, it is adjusted
according to the manufacturer's recommendation.
S6.6 Vehicle openings. All vehicle openings (doors, windows, hood,
trunk, convertible top, cargo doors, etc.) are closed except as required
for instrumentation purposes.
S6.7 Ambient temperature. The ambient temperature is any temperature
between 32 [deg]F. and 100 [deg]F.
S6.8 Wind velocity. The wind velocity is zero.
S6.9 Road surface.
S6.9.1 For vehicles with a GVWR of 10,000 pounds or less, road tests
are conducted on a 12-foot-wide, level roadway, having a skid number of
81. Burnish stops are conducted on any surface. The parking brake test
surface is clean, dry, smooth, Portland cement concrete.
S6.9.2(a) For vehicles with a GVWR greater than 10,000 pounds, road
tests (excluding stability and control during braking tests) are
conducted on a 12-foot-wide, level roadway, having a peak friction
coefficient of 0.9 when measured using an American Society for Testing
and Materials (ASTM) E 1136 standard reference test tire, in accordance
with ASTM Method E 1337-90, at a speed of 40 mph, without water
delivery. Burnish stops are conducted on any surface. The parking brake
test surface is clean, dry, smooth, Portland cement concrete.

[[Page 234]]

S6.9.2(b) For vehicles with a GVWR greater than 10,000 pounds,
stability and control during braking tests are conducted on a 500-foot-
radius curved roadway with a wet level surface having a peak friction
coefficient of 0.5 when measured on a straight or curved section of the
curved roadway using an American Society for Testing and Materials
(ASTM) E1136 standard reference tire, in accordance with ASTM Method
E1337-90, at a speed of 40 mph, with water delivery.
S6.10 Vehicle position and wheel lockup restrictions. The vehicle is
aligned in the center of the roadway at the start of each brake
application. Stops, other than spike stops, are made without any part of
the vehicle leaving the roadway.
S6.10.1 For vehicles with a GVWR of 10,000 pounds or less, stops are
made with wheel lockup permitted only as follows:
(a) At vehicle speeds above 10 mph, there may be controlled wheel
lockup on an antilock-equipped axle, and lockup of not more than one
wheel per vehicle, uncontrolled by an antilock system. (Dual wheels on
one side of an axle are considered a single wheel.)
(b) At vehicle speeds of 10 mph or less, any wheel may lock up for
any duration.
(c) Unlimited wheel lockup is allowed during spike stops (but not
spike check stops), partial failure stops, and inoperative brake power
or power assist unit stops.
S6.10.2 For vehicles with a GVWR greater than 10,000 pounds, stops
are made with wheel lockup permitted only as follows:
(a) At vehicle speeds above 20 mph, any wheel on a nonsteerable axle
other than the two rearmost nonliftable, nonsteerable axles may lock up
for any duration. The wheels on the two rearmost nonliftable,
nonsteerable axles may lock up according to (b).
(b) At vehicle speeds above 20 mph, one wheel on any axle or two
wheels on any tandem may lock up for any duration.
(c) At vehicle speeds above 20 mph, any wheel not permitted to lock
in (a) or (b) may lock up repeatedly, with each lockup occurring for a
duration of one second or less.
(d) At vehicle speeds of 20 mph or less, any wheel may lock up for
any duration.
(e) Unlimited wheel lockup is allowed during partial failure stops,
and inoperative brake power or power assist stops.
S6.11 Thermocouples. The brake temperature is measured by plug-type
thermocouples installed in the approximate center of the facing length
and width of the most heavily loaded shoe or disc pad, one per brake, as
shown in figure 1. A second thermocouple may be installed at the
beginning of the test sequence if the lining wear is expected to reach a
point causing the first thermocouple to contact the metal rubbing
surface of a drum or rotor. For centergrooved shoes or pads,
thermocouples are installed within one-eighth of an inch to one-quarter
inch of the groove and as close to the center as possible.
S6.12 Initial brake temperature. Unless otherwise specified the
brake temperature is 150 [deg]F. to 200 [deg]F.
S6.13 Control forces. Unless otherwise specified, the force applied
to a brake control is not less than 15 lb and not more than 150 lb.
S6.14 Special drive conditions. A vehicle with a GVWR greater than
10,000 pounds equipped with an interlocking axle system or a front wheel
drive system that is engaged and disengaged by the driver is tested with
the system disengaged.
S6.15 Selection of compliance options. Where manufacturer options
are specified, the manufacturer shall select the option by the time it
certifies the vehicle and may not thereafter select a different option
for the vehicle. Each manufacturer shall, upon request from the National
Highway Traffic Safety Administration, provide information regarding
which of the compliance options it has selected for a particular vehicle
or make/model.
S7. Test procedure and sequence. Each vehicle shall be capable of
meeting all the applicable requirements of S5 when tested according to
the procedures and sequence set forth below, without replacing any brake
system part or making any adjustments to the brake system other than as
permitted

[[Page 235]]

in the burnish and reburnish procedures and in S7.9 and S7.10. (For
vehicles only having to meet the requirements of S5.1.1, S5.1.2, S5.1.3,
and S5.1.7 in section S5.1, the applicable test procedures and sequence
are S7.1, S7.2, S7.4, S7.5(b), S7.5(a), S7.8, S7.9, S7.10, and S7.18.
However, at the option of the manufacturer, the following test procedure
and sequence may be conducted: S7.1, S7.2, S7.3, S7.4, S7.5(b), S7.6,
S7.7, S7.5(a), S7.8, S7.9, S7.10, and S7.18. The choice of this option
must not be construed as adding to the requirements specified in S5.1.2
and S5.1.3.) Automatic adjusters must remain activated at all times. A
vehicle shall be deemed to comply with the stopping distance
requirements of S5.1 if at least one of the stops at each speed and load
specified in each of S7.3, S7.5(b), S7.8, S7.9, S7.10, S7.15 and S7.17
(check stops) is made within a stopping distance that does not exceed
the corresponding distance specified in Table II. When the transmission
selector control is required to be in neutral for a deceleration, a stop
or snub must be obtained by the following procedures:
(a) Exceed the test speed by 4 to 8 mph;
(b) Close the throttle and coast in gear to approximately 2 mph
above the test speed;
(c) Shift to neutral; and
(d) When the test speed is reached, apply the service brakes.
S7.1 Brake warming. If the initial brake temperature for the first
stop in a test procedure (other than S7.7 and S7.16) has not been
reached, heat the brakes to the initial brake temperature by making not
more than 10 snubs from not more than 40 to 10 mph, at a deceleration
not greater than 10 fpsps.
S7.2 Pretest instrumentation check. Conduct a general check of
instrumentation by making not more than 10 stops from a speed of not
more than 30 mph, or 10 snubs from a speed of not more than 40 to 10
mph, at a deceleration of not more than 10 fpsps. If instrument repair,
replacement, or adjustment is necessary, make not more than 10
additional stops or snubs after such repair, replacement, or adjustment.
S7.3 Service brake system--first (preburnish) effectiveness test.
Make six stops from 30 mph. Then make six stops from 60 mph.
S7.4 Service brake system--burnish procedure.
S7.4.1 Vehicles with GVWR of 10,000 lb or less.
S7.4.1.1 Burnish. Burnish the brakes by making 200 stops from 40 mph
at 12 fpsps (the 150 lb control force limit does not apply here). The
interval from the start of one service brake application to the start of
the next shall be either the time necessary to reduce the initial brake
temperature to between 230 [deg]F. and 270 [deg]F., or the distance of 1
mile, whichever occurs first. Accelerate to 40 mph after each stop and
maintain that speed until making the next stop.
S7.4.1.2 Brake adjustment--post burnish. After burnishing, adjust
the brakes in accordance with the manufacturer's published
recommendations.
S7.4.2 Vehicles with GVWR greater than 10,000 pounds.
S7.4.2.1 Burnish. Vehicles are burnished according to the following
procedures. Make 500 snubs between 40 mph and 20 mph at a deceleration
rate of 10 f.p.s.p.s. Except where an adjustment is specified, after
each brake application accelerate to 40 mph and maintain that speed
until making the next brake application at a point 1 mile from the
initial point of the previous brake application. If the vehicle cannot
attain a speed of 40 mph in 1 mph, continue to accelerate until the
vehicle reaches 40 mph or until the vehicle has traveled 1.5 miles from
the initial point of the previous brake application, whichever occurs
first. The brakes shall be adjusted three times during the burnish
procedure, in accordance with the manufacturer's recommendations, after
125, 250, and 375 snubs.
S7.4.2.2 Brake adjustment--post burnish. After burnishing, adjust
the brakes in accordance with the manufacturer's published
recommendations.
S7.5 (a) Stability and control during braking (vehicles with a GVWR
greater than 10,000 pounds). Make four stops in the lightly-loaded
weight condition specified in S5.1.7. Use a full brake application for
the duration of the stop, with the clutch pedal depressed or the
transmission selector control in the

[[Page 236]]

neutral position, for the duration of each stop.
(b) Service brake system--second effectiveness test. For vehicles
with a GVWR of 10,000 pounds or less, or any school bus, make six stops
from 30 mph. Then, for any vehicle, make six stops from 60 mph. Then,
for a vehicle with a GVWR of 10,000 pounds or less, make four stops from
80 mph if the speed attainable in 2 miles is not less than 84 mph.
S7.6 First reburnish. Repeat S7.4, except make 35 burnish stops or
snubs. In the case of vehicles burnished in accordance with S7.4.2.1(a)
of this section, reburnish the vehicle by making 35 snubs from 60 to 20
mph, but if the hottest brake temperature reaches 500 [deg]F 50 [deg]F, make the remainder of the brake applications
from the highest snub condition listed in Table IV that will maintain
the hottest brake temperature at 500 [deg]F 50
[deg]F. If at a snub condition of 40 to 20 mph, the temperature of the
hottest brake exceeds 550 [deg]F, make the remainder of the 35 brake
applications from the snub condition without regard to brake
temperature.
S7.7 Parking brake test. The parking brake tests for any vehicle on
different grades, in different directions, and for different loads may
be conducted in any order. The force required for actuation of a hand-
operated brake system shall be measured at the center of the hand grip
area or at a distance of 1\1/2\ inches from the end of the actuation
lever, as illustrated in Figure II.
S7.7.1 Test procedure for requirements of S5.2.1 and S5.2.3.
S7.7.1.1 Condition the parking brake friction elements so that the
temperature at the beginning of the test is at any level not more than
150 [deg]F. (when the temperature of components on both ends of an axle
are averaged).
S7.7.1.2 Drive the vehicle, loaded to GVWR, onto the specified grade
with the longitudinal axis of the vehicle in the direction of the slope
of the grade, stop the vehicle and hold it stationary by application of
the service brake control, and place the transmission in neutral.
S7.7.1.3 With the vehicle held stationary by means of the service
brake control, apply the parking brake by a single application of the
force specified in (a), (b), or (c) of this paragraph, except that a
series of applications to achieve the specified force may be made in the
case of a parking brake system design that does not allow the
application of the specified force in a single application:
(a) In the case of a passenger car or other vehicle with a GVWR of
10,000 lbs. or less, not more than 125 pounds for a foot-operated
system, and not more than 90 pounds for a hand-operated system; and
(b) In the case of a vehicle with a GVWR greater than 4,536
kilograms (10,000 pounds) not more than 150 pounds for a foot-operated
system, and not more than 125 pounds for a hand-operated system.
(c) For a vehicle using an electrically-activated parking brake,
apply the parking brake by activating the parking brake control.
S7.7.1.4 Following the application of the parking brake in
accordance with S7.7.1.3, release all force on the service brake control
and commence the measurement of time if the vehicle remains stationary.
If the vehicle does not remain stationary, reapplication of the service
brake to hold the vehicle stationary, with reapplication of a force to
the parking brake control at the level specified in S7.7.1.3 (a) or (b)
as appropriate for the vehicle being tested (without release of the
ratcheting or other holding mechanism of the parking brake) may be used
twice to attain a stationary position.
S7.7.1.5 Following observation of the vehicle in a stationary
condition for the specified time in one direction, repeat the same test
procedure with the vehicle orientation in the opposite direction on the
specified grade.
S7.7.1.6 Check the operation of the parking brake application
indicator required by S5.3.1(d).
S7.7.2 Test procedure for requirements of S5.2.2 (a) Check that
transmission must be placed in park position to release key;
(b) Test as in S7.7.1, except in addition place the transmission
control to engage the parking mechanism; and
(c) Test as in S7.7.1 except on a 20 percent grade, with the parking
mechanism not engaged.

[[Page 237]]

S7.7.3 Lightly loaded vehicle. Repeat S7.7.1 or S7.7.2 as applicable
except with the vehicle at lightly loaded vehicles weight or at
manufacturer's option, for a vehicle with GVWR greater than 10,000
pounds, at lightly loaded vehicle weight plus not more than an
additional 1,000 pounds for a roll bar structure on the vehicle.
S7.7.4 Non-service brake type parking brake systems. For vehicles
with parking brake systems not utilizing the service brake friction
elements, burnish the friction elements of such systems prior to parking
brake tests according to the manufacturer's published recommendations as
furnished to the purchaser. If no recommendations are furnished, run the
vehicle in an unburnished condition.
S7.8 Service brake system test--lightly loaded vehicle (third
effectiveness) test. Make six stops from 60 mph with vehicle at lightly
vehicle weight, or at the manufacturer's option for a vehicle with GVWR
greater than 10,000 pounds, at lightly loaded vehicle weight plus not
more than an additional 1,000 pounds for a roll bar structure on the
vehicle. (This test is not applicable to a vehicle which has a GVWR of
not less than 7,716 pounds and not greater than 10,000 pounds and is not
a school bus.)
S7.9 Service brake system test--partial failure.
S7.9.1 With the vehicle at lightly loaded vehicle weight or at the
manufacturer's option for a vehicle with a GVWR greater than 10,000
pounds, at lightly loaded vehicle weight plus not more than an
additional 1,000 pounds for a roll bar structure on the vehicle, alter
the service brake system to produce any one rupture or leakage type of
failure, other than a structural failure of a housing that is common to
two or more subsystems. Determine the control force, pressure level, or
fluid level (as appropriate for the indicator being tested) necessary to
activate the brake system indicator lamp. Make four stops if the vehicle
is equipped with a split service brake system, or 10 stops if the
vehicle is not so equipped, each from 60 mph, by a continuous
application of the service brake control. Restore the service brake
system to normal at completion of this test.
S7.9.2 Repeat S7.9.1 for each of the other subsystems.
S7.9.3 Repeat S7.9.1 and S7.9.2 with vehicle at GVWR. Restore the
service brake system to normal at completion of this test.
S7.9.4 (For vehicles with antilock and/or variable proportioning
brake systems.) With vehicle at GVWR, disconnect functional power
source, or otherwise render antilock system inoperative. Disconnect
variable proportioning brake system. Make four stops, each from 60 mph.
If more than one antilock or variable proportioning brake subsystem is
provided, disconnect or render one subsystem inoperative and run as
above. Restore system to normal at completion of this test. Repeat for
each subsystem provided.
Determine whether the brake system indicator lamp is activated when
the electrical power source to the antilock or variable proportioning
unit is disconnected.
S7.9.5 For a vehicle in which the brake signal is transmitted
electrically between the brake pedal and some or all of the foundation
brakes, regardless of the means of actuation of the foundation brakes,
the tests in S7.9.1 through S7.9.3 of this standard are conducted by
inducing any single failure in any circuit that electrically transmits
the brake signal, and all other systems intact. Determine whether the
brake system indicator lamp is activated when the failure is induced.
S7.9.6 For an EV with RBS that is part of the service brake system,
the tests specified in S7.9.1 through S7.9.3 are conducted with the RBS
disconnected and all other systems intact. Determine whether the brake
system indicator lamp is activated when the RBS is disconnected.
S7.10 Service brake system--inoperative brake power unit or brake
power assist unit test. (For vehicles equipped with brake power unit or
brake power assist unit.)
S7.10.1 Regular procedure. (This test need not be run if the option
in S7.10.2 is selected.) On vehicles with brake power assist units,
render the brake power assist unit inoperative, or one of the brake
power assist unit subsystems

[[Page 238]]

if two or more subsystems are provided, by disconnecting the relevant
power supply. Exhaust any residual brake power reserve capability of the
disconnected system. On vehicles with brake power units, disconnect the
primary source of power. Make four stops, each from 60 mph by a
continuous application of the service brake control. Restore the system
to normal at completion of this test. For vehicles equipped with more
than one brake power unit or brake power assist unit, conduct tests of
each in turn.
S7.10.2 Optional Procedures. On vehicles with brake power assist
units, the unit is charged to maximum prior to start of test. (Engine
may be run up in speed, then throttle closed quickly to attain maximum
charge on vacuum assist units.) Brake power units shall also be charged
to maximum accumulator pressure prior to start of test. No recharging is
allowed after start of test.
(a) (For vehicles with brake power assist units.) Disconnect the
primary source of power. Make six stops each from 60 mph, to achieve the
average deceleration for each stop as specified in table III. Apply the
brake control as quickly as possible. Maintain control force until
vehicle has stopped.

At the completion of the stops specified above, deplete the system of
any residual brake power reserve capability. Make one stop from 60 mph
at an average deceleration of not lower than 7 fpsps for passenger cars
(equivalent stopping distance 554 feet), or 6 fpsps for vehicles other
than passenger cars (equivalent stopping distance 646 feet) and
determine whether the control force exceeds 150 pounds.
(b) (For vehicles with brake power units with accumulator type
systems.) Test as in S7.10.2(a), except make 10 stops instead of 6 and,
at the completion of the 10 stops, deplete the failed element of the
brake power unit of any residual brake power reserve capability before
making the final stop.
(c) (For vehicles with brake power assist or brake power units with
backup systems.) If the brake power or brake power assist unit operates
in conjunction with a backup system and the backup system is activated
automatically in the event of a primary power failure, the backup system
is operative during this test. Disconnect the primary source of power of
one subsystem. Make 15 stops, each from 60 mph, with the backup system
activated for the failed subsystem, to achieve an average deceleration
of 12 fpsps for each stop.
(d) Restore systems to normal at completion of these tests. For
vehicles equipped with more than one brakepower assist or brakepower
unit, conduct tests of each in turn.
S7.10.3 Electric brakes.
(a) For vehicles with electrically-actuated service brakes, the
tests in S7.10.1 or S7.10.2 are conducted with any single electrical
failure in the electric brake system instead of the brake power or brake
power assist systems, and all other systems intact.
(b) For EVs with RBS that is part of the service brake system, the
tests in S7.10.1 or S7.10.2 are conducted with the RBS discontinued and
all other systems intact.
S7.11 Service brake system--first fade and recovery test.
S7.11.1 Baseline check stops or snubs.
S7.11.1.1 Vehicles with GVWR of 10,000 lb or less. Make three stops
from 30 mph at 10 fpsps for each stop. Control force readings may be
terminated when vehicle speed falls to 5 mph. Average the maximum brake
control force required for the three stops.
S7.11.1.2 Vehicles with GVWR greater than 10,000 pounds. With
transmission in neutral (or declutched), make three snubs from 40 to 20
mph at 10 fpsps for each snub. Average the maximum brake control force
required for the three snubs.
S7.11.2 Fade stops or snubs.
S7.11.2.1 Vehicles with GVWR of 10,000 pounds or less. Make 5 stops
from 60 mph at 15 fpsps followed by 5 stops at the maximum attainable
deceleration between 5 and 15 fpsps for each stop. Establish an initial
brake temperature before the first brake application of 130[deg] to 150
[deg]F. Initial brake temperatures before brake applications for
subsequent stops are those occurring at the distance intervals. Attain
the required deceleration within 1 second and, as a minimum, maintain it
for the remainder of the stopping time. Control force readings may be
terminated

[[Page 239]]

when vehicle speed falls to 5 mph. Leave an interval of 0.4 mi between
the start of brake applications. Accelerate immediately to the initial
test speed after each stop. Drive 1 mi at 30 mph after the last fade
stop, and immediately follow the recovery procedure specified in
S7.11.3.1.
S7.11.2.2 Vehicles with GVWR greater than 10,000 lb. With
transmission in neutral (or declutched) make 10 snubs from 40 to 20 mph
at 10 fpsps for each snub. Establish an initial brake temperature before
the first brake application of 130 [deg]F. to 150 [deg]F. Initial brake
temperatures before brake application for subsequent snubs are those
occurring in the time intervals specified below. Attain the required
deceleration within 1 s and maintain it for the remainder of the
snubbing time. Leave an interval of 30 s between snubs (start of brake
application to start of brake application). Accelerate immediately to
the initial test speed after each snub. Drive for 1.5 mi at 40 mph after
the last snub and immediately follow the recovery procedure specified in
S7.11.3.2.
S7.11.3 Recovery stops or snubs.
S7.11.3.1 Vehicles with GVWR of 10,000 lb or less. Make five stops
from 30 mph at 10 fpsps for each stop. Control force readings may be
terminated when vehicle speed falls to 5 mph. Allow a braking distance
interval of 1 mi. Immediately after each stop accelerate at maximum rate
to 30 mph and maintain that speed until making the next stop. Record the
maximum control force for each stop.
S7.11.3.2 Vehicles with GVWR greater than 10,000 lb. With
transmission in neutral (or declutched) make five snubs from 40 to 20
mph at 10 fpsps for each snub. After each snub, accelerate at maximum
rate to 40 mph and maintain that speed until making the next brake
application at a point 1.5 mi from the point of the previous brake
application. Record the maximum control force for each snub.
S7.12 Service brake system--second reburnish. Repeat S7.6.
S7.13 Service brake system--second fade and recovery test. Repeat
S7.11 except in S7.11.2 run 15 fade stops or 20 snubs instead of 10.
S7.14 Third reburnish. Repeat S7.6.
S7.15 Service brake system--fourth effectiveness test. Repeat S7.5.
Then (for passenger cars) make four stops from either 95 mph if the
speed attainable in 2 mi is 99 to (but not including) 104 mph, or 100
mph if the speed attainable in 2 mi is 104 mph or greater.
S7.16 Service brake system--water recovery test.
S7.16.1 Baseline check stop. Make three stops from 30 mph at 10
fpsps for each stop. Control force readings may be terminated when
vehicle speed falls to 5 mph. Average the maximum brake control force
required for the three stops.
S7.16.2 Wet brake recovery stops. With the brakes fully released at
all times, drive the vehicle for 2 min at a speed of 5 mph in any
combination of forward and reverse directions, through a trough having a
water depth of 6 in. After leaving the trough, immediately accelerate at
a maximum rate to 30 mph without a brake application. Immediately upon
reaching that speed make five stops, each from 30 mph at 10 fpsps for
each stop. After each stop (except the last), accelerate the vehicle
immediately at a maximum rate to a speed of 30 mph and begin the next
stop.
S7.17 Spike stops. Make 10 successive spike stops from 30 mph with
the transmission in neutral, with no reverse stops. Make spike stops by
applying a control force of 200 lb while recording control force versus
time. Maintain control force until vehicle has stopped. At completion of
10 spike stops, make six effectiveness stops from 60 mph.
S7.18 Final inspection. Inspect--
(a) The service brake system for detachment or fracture of any
components, such as brake springs and brake shoes or disc pad facing.
(b) The friction surface of the brake, the master cylinder or brake
power unit reservoir cover and seal and filler openings, for leakage of
brake fluid or lubricant.
(c) The master cylinder or brake power unit reservoir for compliance
with the volume and labeling requirements of S5.4.2 and S5.4.3. In
determining the fully applied worn condition assume that the lining is
worn to: (1) Rivet or bolt heads on riveted or bolted linings, or (2)
within one thirty-

[[Page 240]]

seconds of an inch of shoe or pad mounting surface on bonded linings, or
(3) the limit recommended by the manufacturer, whichever is larger
relative to the total possible shoe or pad movement. Drums or rotors are
assumed to be at nominal design drum diameter or rotor thickness.
Linings are assumed adjusted for normal operating clearance in the
released position.
(d) The brake system indicator light(s), for compliance with
operation in various key positions, lens color, labeling, and location,
in accordance with S5.3.
S7.19 Moving barrier test. (Only for vehicles that have been tested
according to S7.7.2.) Load the vehicle to GVWR, release parking brake,
and place the transmission selector control to engage the parking
mechanism. With a moving barrier as described in paragraph 4.3 of SAE
recommended practice J972 ``Moving Barrier Collision Tests,'' Nov. 1966
(revised May 2000), impact the vehicle from the front at 2\1/2\ mph.
This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies may be obtained from the Society of Automotive Engineers, Inc.,
400 Commonwealth Drive, Warrendale, PA 15096-0001. Copies may be
inspected at the National Highway Traffic Safety Administration,
Technical Information Services, 400 Seventh Street, SW., Plaza Level,
Room 403, Washington, DC 20590, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
Keep the longitudinal axis of the barrier parallel with the longitudinal
axis of the vehicle. Repeat the test, impacting the vehicle from the
rear.

Note: The vehicle used for this test need not be the same vehicle
that has been used for the braking tests.
[GRAPHIC] [TIFF OMITTED] TC01AU91.004

Figure 1--Typical Plug Thermocouple Installations
Note: The second thermocouple shall be installed at .080 inch depth
within 1 inch circumferentially of the thermocouple installed at .040
inch depth.

[[Page 241]]

[GRAPHIC] [TIFF OMITTED] TC01AU91.005

Table I--Brake Test Procedure Sequence and Requirements
----------------------------------------------------------------------------------------------------------------
Test load
Sequence ---------------------------------- Test procedure Requirements
Light GVWR
----------------------------------------------------------------------------------------------------------------
1. Instrumentation check......... ............... ............... S7.2 ...................
2. First (preburnish) ............... X S7.3.................. S5.1.1.1
effectiveness test.
3. Burnish procedure............. ............... X S7.4 ...................
4. Second effectiveness test..... ............... X S7.5(b)............... S5.1.1.2
5. First reburnish............... ............... X S7.6.................. ...................
6. Parking brake................. X X S7.7.................. S5.2
7. Stability and control during X ............... S7.5(a)............... S5.1.7
braking (braking-in-a-curve
test).
8. Third effectiveness (lightly X ............... S7.8.................. S5.1.1.3
loaded vehicle).
9. Partial failure............... X X S7.9.................. S5.1.2
10. Inoperative brake power and ............... X S7.10................. S5.1.3
power assist units.
11. First fade and recovery...... ............... X S7.11................. S5.1.4
12. Second reburnish............. ............... X S7.12 ...................
13. Second fade and recovery..... ............... X S7.13................. S5.1.4
14. Third reburnish.............. ............... X S7.14 ...................
15. Fourth effectiveness......... ............... X S7.15................. S5.1.1.4
16. Water recovery............... ............... X S7.16................. S5.1.5
17. Spike stops.................. ............... X S7.17................. S5.1.6
18. Final inspection............. ............... ............... S7.18................. S5.6
19. Moving barrier test.......... ............... X S7.19................. S5.2.2.3
----------------------------------------------------------------------------------------------------------------

[[Page 242]]

[GRAPHIC] [TIFF OMITTED] TR07SE99.007

Table III--Inoperative Brake Power Assist and Brake Power Units
----------------------------------------------------------------------------------------------------------------
Average deceleration, FPSPS Equivalent stopping distance, feet
-----------------------------------------------------------------------------------
Column 1--brake Column 2--brake Column 3--brake Column 4--brake
Stop No. power assist power unit power assist power unit
-----------------------------------------------------------------------------------
(b) and (b) and (b) and (b) and
(a) (c) (a) (c) (a) (c) (a) (c)
----------------------------------------------------------------------------------------------------------------
1........................... 16.0 14.0 16.0 13.0 242 277 242 298
2........................... 12.0 12.0 13.0 11.0 323 323 298 352
3........................... 10.0 10.0 12.0 10.0 388 388 323 388
4........................... 9.0 8.5 11.0 9.5 431 456 352 409
5........................... 8.0 7.5 10.0 9.0 484 517 388 431
6........................... 7.5 6.7 9.5 8.5 517 580 409 456
7........................... \1\ 7.0 \1\ 6.0 9.0 8.0 554 646 431 484
8........................... NA NA 8.5 7.5 NA NA 456 517
9........................... NA NA 8.0 7.0 NA NA 484 554
10.......................... NA NA 7.5 6.5 NA NA 517 596
11.......................... NA NA \1\ 7.0 \1\ 6.0 NA NA 554 646
----------------------------------------------------------------------------------------------------------------
\1\ Depleted. (a) Passenger cars; (b) vehicles other than passenger cars with GVWR of 10,000 lbs or less; (c)
vehicles with GVWR greater than 10,000 lbs; NA=Not applicable.

[41 FR 29696, July 19, 1976; 41 FR 32221, Aug. 2, 1976, as amended at 41
FR 36026, 36027, Aug. 26, 1976; 43 FR 9606, Mar. 9, 1978; 46 FR 64, Jan.
2, 1981; 46 FR 21180, Apr. 9, 1981; 47 FR 61893, Dec. 21, 1981; 48 FR
39941, Sept. 2, 1983; 49 FR 30199, July 27, 1984; 52 FR 19874, May 28,
1987; 53 FR 8200, Mar. 14, 1988; 54 FR 22905, May 30, 1989; 54 FR 40082,
Sept. 29, 1989; 57 FR 47800, Oct. 20, 1992; 58 FR 45461, Aug. 30, 1993;
60 FR 6434, Feb. 2, 1995; 60 FR 13256 and 13303, Mar. 10, 1995; 61 FR
19562, May 2, 1996; 62 FR 46917, Sept. 5, 1997; 62 FR 51069, Sept. 30,
1997; 64 FR 9449, Feb. 26, 1999; 64 FR 48564, Sept. 7, 1999; 65 FR 6331,
Feb. 9, 2000; 68 FR 47495, Aug. 11, 2003; 67 FR 79439, Dec. 27, 2002; 69
FR 75488, Dec. 17, 2004; 70 FR 37713, June 30, 2005]