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Federal Motor Vehicle Safety Standards, Passenger Car Brake Systems Publication: Federal Register Agency: National Highway Traffic Safety Administration Byline: Ricardo Martinez Date: 24 July 1995 Subject: American Government 
Topic: Federal Motor Vehicle Safety Standards |
[Federal Register Volume 60, Number 141 (Monday, July 24, 1995)]
[Rules and Regulations]
[Pages 37844-37848]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-18106]
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DEPARTMENT OF TRANSPORTATION
49 CFR Part 571
[Docket No. 85-06; Notice 9]
RIN 2127-AF82
Federal Motor Vehicle Safety Standards, Passenger Car Brake
Systems
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule; Response to petitions for reconsideration.
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SUMMARY: In February 1995, NHTSA published a new Federal Motor Vehicle
Safety Standard No. 135, Passenger Car Brake Systems, which replaces
the existing Standard No. 105, Hydraulic Brake Systems, as it applies
to passenger cars. The agency's action was part of its efforts to
harmonize its standards with international standards. The agency
received three petitions for reconsideration, each of which supported
the new standard, but recommended one or more changes. This document
provides NHTSA's response to those petitions. As part of its response,
the agency is making several minor changes in the standard's test
conditions. NHTSA is also making a number of correcting amendments to
the new standard.
DATES: Effective date. The amendments made by this rule are effective
August 23, 1995.
Petitions for reconsideration. Petitions for reconsideration must
be received not later than August 23, 1995.
ADDRESSES: Petitions for reconsideration should be submitted to:
Administrator, National Highway Traffic Safety Administration, 400
Seventh Street SW., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Ms. Terri Droneburg, Office of Vehicle
Safety Standards, National Highway Traffic Safety Administration, 400
Seventh Street SW., Room 5307, Washington, DC 20590. Phone: (202) 366-
6617. Fax: (202) 366-4329.
SUPPLEMENTARY INFORMATION: On February 2, 1995, NHTSA published in the
Federal Register (60 FR 6411) a final rule establishing Federal Motor
Vehicle Safety Standard No. 135, Passenger Car Brake Systems. That
standard will replace Standard No. 105, Hydraulic Brake Systems, as it
applies to passenger cars.
NHTSA received petitions for reconsideration from General Motors
(GM), the Japan Automobile Manufacturers Association (JAMA), and
Mercedes-Benz. Each of the petitioners supported the establishment of
the new standard, but identified one or more areas where they
recommended changes. The issues raised by the petitioners are addressed
below.
GM first identified several technical corrections to make in the
text of Standard No. 135. NHTSA concurs with these corrections and has
also identified several other corrections that need to be made. In this
document, the agency is making those corrections.
GM next identified one substantive area of concern, involving the
pedal force constraints for the hot and recovery performance tests
(S7.14.3(c) and S7.16.3(c)). GM stated that NHTSA had explained in the
final rule that Standard No. 135 is intended to ensure that faded
brakes are capable of achieving both a minimum level of performance
relative to cold effectiveness (i.e., at least 60 percent of cold
effectiveness deceleration) and a minimum absolute level of performance
(i.e., stopping distance less than or equal to 89 meters, from a speed
of 100 km/h (62.1 mph)).
GM stated that, to make the relative performance a true comparison,
it is necessary to constrain the hot stop pedal force to that which was
used during the cold effectiveness stop. GM stated also that only by
having similar pedal force profiles between the hot and cold stops is
it possible to effectively compare hot and cold brake performance. That
company cited the agency's statement in the final rule preamble that,
``(i)n order for that comparison to be meaningful, the test conditions
for the two tests should be as close to identical as possible.''
GM argued, however, that the language adopted in the final rule
does not facilitate test conditions for the cold and hot stops that are
as close to identical as possible. GM said that the language instead
precludes a legitimate comparison between hot and cold performance by
forcing a significantly different pedal force on the hot stop. GM
stated that a typical pedal force profile used during cold
effectiveness testing shows an initial spike, followed by a lower,
level force. That company stated that because the language of the final
rule limits the peak hot stop pedal force to the average cold
effectiveness pedal force, it precludes the use of an initial spike for
the comparison hot stop. GM stated that this shortcoming can be easily
corrected by amending the regulatory language to state that the
[[Page 37845]]
average hot stop pedal force cannot exceed the average cold
effectiveness pedal force. GM also stated that the same analysis
applies to the pedal force constraint for recovery performance.
NHTSA has evaluated GM's arguments and agrees that the suggested
changes would make the test conditions for the cold, hot, and recovery
stops more similar and thereby make the results more comparable. The
agency is therefore adopting those suggested amendments.
GM also identified three areas for potential future rulemaking
concerning Standard No. 135. First, that company stated that, even if
the agency adopts its recommended changes concerning pedal force, two
minor flaws will remain with the thermal test protocols. GM stated:
First, a considerable amount of testing is performed between the
cold effectiveness test (which serves as the baseline for thermal
performance) and the thermal tests. These intervening tests can
introduce distortions to the hot versus cold comparisons by virtue
of brake and tire conditioning, changing environmental conditions,
etc. Second, the pedal force spike input during the cold
effectiveness test may be difficult to precisely replicate in the
subsequent thermal tests. These two flaws could be corrected by
adopting constant pedal force cold stops at the onset of the thermal
test sequence to be used as the baseline comparison stops. The
preamble to Notice 8 implies that the agency will not take action in
this area until U.S. and European manufacturers come forward with a
recommendation. GM requests that the agency initiate this process
with either a Request for Comments or Advance Notice of Proposed
Rulemaking.
While NHTSA has considered this request of GM, the agency does not
believe that further rulemaking on this particular issue is warranted
at this time. The agency notes that different manufacturers have
significantly different views on this issue and that while GM believes
it is an area where Standard No. 135 could be improved, that company
has not provided information demonstrating that the current procedure
creates any significant problems, e.g., compliance difficulties, effect
on safety, etc. The agency also believes that the issue is only
relevant for vehicles that do not have ABS. Since it is expected that
nearly all passenger cars will soon have ABS, the issue will
essentially become moot.
GM also noted that NHTSA is conducting rulemaking to amend
Standards No. 105 and 135 to ensure their appropriateness for electric
vehicles and electric brakes, and urged the agency to move as quickly
as possible in this area. NHTSA notes that it is in the process of
completing a new notice on that subject and expects to issue it
shortly.
GM also recommended that the agency initiate rulemaking to extend
Standard No. 135 to all hydraulically braked vehicles. The agency notes
that it plans to conduct rulemaking to extend the standard to all
vehicles with a GVWR of 10,000 pounds or less.
JAMA petitioned NHTSA to change the temperature range specified for
initial brake temperature for the cold brake effectiveness test. While
the final rule specifies a range of 50 deg.C to 100 deg.C, that
petitioner recommended a range of 65 deg.C to 100 deg.C.
JAMA noted that its recommended range is similar to that specified
in Standard No. 105. That organization argued that the wider range
would impose increased cost burdens since vehicles must meet the
requirements at all points within the range.
Upon reconsideration, NHTSA agrees that the lower limit of the
initial brake temperature should be changed to 65 deg.C. This limit is
nearly identical to that specified in Standard No. 105. Moreover, while
some drafts of Regulation 13-H (the proposed harmonized regulation
developed by the United Nations Economic Commission for Europe)
included the 50 deg.C value, it was changed to 65 deg. in 1991. Since
the 65 deg. value is consistent with both Standard No. 105 and the
most recent draft of Regulation 13-H, and since it results in decreased
variability in test results, NHTSA believes that this change
recommended by JAMA should be made.
JAMA also recommended that the agency amend the definition of
``initial brake temperature'' to read ``* * * on the hottest brake,''
rather than ``* * * on the hottest axle.'' That organization stated
that this change would eliminate a lack of international harmonization
without any detriment to motor vehicle safety.
The agency has decided not to accept this recommendation of JAMA.
NHTSA believes the initial brake temperature should be based on the
hottest axle rather than the hottest brake, to ensure that one brake
does not cause an unrealistically high value for the initial brake
temperature.
Mercedes petitioned the agency to change Standard No. 135's
requirements concerning indication of brake wear status. That company
noted that the standard specifies that, if a separate indicator is used
to indicate brake lining wear, the words ``Brake Wear'' must be used.
Mercedes requested that the agency permit the use of the international
symbol for brake wear. This symbol consists of a circle, with a dotted
curved line on each side of the circle. That company argued that there
are no data indicating a safety need for words versus an international
symbol. Mercedes also stated that, when marketing a car in nearly 200
countries, it is highly impractical to use native language text.
NHTSA notes that Mercedes stated that it and other manufacturers
can meet the requirements in this area by another alternative permitted
by Standard No. 135, i.e., providing a means of visually inspecting
brake pad thickness with the wheels removed. That company asserted
that, as a result of complying with this alternative, ``(a)n in-dash
brake wear warning lamp with an international symbol, not Standard 135
words, can be voluntarily provided, and is, therefore not prohibited by
Standard 135.'' In support of its position, Mercedes stated that
``NHTSA's Chief Counsel has reiterated in numerous interpretations
that, unless specifically prohibited, manufacturers may voluntarily
provide more features or information than required by a Safety
Standard.'' The petitioner stated, however, that even with such options
available, it believes it is important that the final rule be amended
to permit the international symbol. Among other things, Mercedes stated
that future electric and hybrid cars may not be able to meet the
relevant requirements of Standard No. 135 by providing a means of wheel
removal and inspection, due to weight reduction and other critical
design conflicts.
NHTSA has carefully considered Mercedes' request. For reasons
discussed below, the agency has decided not to make the requested
change at this time. However, the agency will consider that
petitioner's request in a separate rulemaking proceeding which will
more broadly address the use of symbols for brake system indicators.
The agency will begin its response to Mercedes by addressing that
company's belief that, so long as a manufacturer provides a means of
visually inspecting brake pad thickness with the wheels removed (in
accordance with the alternative specified in S5.1.2(b) of Standard No.
135), it can voluntarily provide an in-dash brake wear warning lamp
with an international symbol instead of the words specified by that
standard. The agency concurs with this result, based on a reading of
S5.1.2, S5.5.1, and S5.5.5 of Standard No. 135, as well as Standard No.
101.
Of particular significance, Standard No. 135's requirement to use
specified
[[Page 37846]]
words for a brake wear indicator lamp (S5.5.5(d)(5)) is expressed as
follows:
If a separate indicator is provided to indicate brake lining
wear-out as specified in S5.5.1(d), the words ``Brake Wear'' shall
be used.
S5.5.1(d), which specifies one of the conditions for which a brake
indicator must be activated, reads as follows:
Brake lining wear-out, if the manufacturer has elected to use an
electrical device to provide an optical warning to meet the
requirements of S5.1.2(a).
Since S5.5.5(d)(5)'s wording requirement applies to a separate
indicator provided to indicate brake lining wear-out ``as specified in
S5.5.1(d),'' and since S5.5.1(d) only applies where a manufacturer has
``elected'' to use an electrical device to meet the standard's brake
wear status requirement, it is NHTSA's interpretation that the wording
requirement does not apply where a manufacturer has elected options
other than an electrical device to provide an optical warning.
Therefore, the agency concurs with the result suggested by Mercedes,
although not necessarily with the petitioner's stated rationale.
NHTSA notes that Mercedes is correct that, unless specifically
prohibited, manufacturers may voluntarily provide more features or
information than required by a safety standard. The agency cautions,
however, that this principle, by itself, does not necessarily mean that
voluntarily provided safety features are not subject to particular
requirements set forth in a safety standard. Such a result could be
highly dependent on a specific factual situation and on the specific
wording of a safety standard. If a manufacturer has a question about
how a safety standard applies in a specific situation, it may, of
course, request an interpretation from NHTSA's Chief Counsel.
NHTSA will now address Mercedes' request that Standard No. 135 be
amended to permit use of the international symbol for worn brake
linings instead of the words ``brake wear.'' The agency notes that
Standard No. 135 specifies the use of words for several brake indicator
functions, and that the international symbol for worn brake linings is
part of a family of related symbols which address a number of brake
functions. Therefore, Mercedes' request is part of a broader issue of
whether Standard No. 135 should permit the use of symbols instead of
words for the various brake indicator functions.
In the preamble to the February 1995 final rule, NHTSA stated:
Notice 5 and this final rule (Section S5.5.5(a)) allow the use
of ISO symbols in addition to the required labeling for the purpose
of clarity. However, the agency has decided not to allow the ISO
symbol alone to be used as a substitute for the required words.
NHTSA believes that the ISO symbol can be ambiguous to some drivers
since the ISO symbol, is not universally understood to represent
brakes. The agency notes that the commenters did not provide any
data showing that the ISO brake failure warning indicator is clearly
understood by drivers in countries in which it is currently in use.
Moreover, the meaning of the symbol is not readily apparent from its
appearance, in contrast to some symbols, such as the one for horns,
whose meaning is understandable on its face. 60 FR 6414, February 2,
1995.
NHTSA has decided to conduct a separate proceeding in which it will
reconsider permitting the use of symbols for brake system indicators.
The agency believes that, before making any change in this area,
specific comment should be sought on each of the symbols in question
and on what steps can be taken to ensure that drivers would learn the
meaning of the symbols.
NHTSA is granting the petitions to the extent discussed above; the
agency is otherwise denying the petitions.
The agency is making the amendments effective 30 days after
publication of the final rule. NHTSA finds good cause for such an
effective date. The amendments do not impose any new requirements or
make existing requirements more stringent. The amendments instead
either make corrections in the new standard or very minor changes in
the test conditions specified by the standard.
Rulemaking Analyses and Notices
Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures
This notice was not reviewed under Executive Order 12866. NHTSA has
examined the impact of this rulemaking action and determined that it is
not ``significant'' within the meaning of the Department of
Transportation's regulatory policies and procedures. NHTSA has further
determined that the effects of this rulemaking are so minimal that
preparation of a full regulatory evaluation is not warranted. The
effects of today's rule are minimal because the rule makes only very
minor changes in the test conditions specified by Standard No. 135. The
rule will not have any quantifiable impact on testing costs or vehicle
costs. The agency's detailed analysis of the economic effects of
Standard No. 135, set forth in the Final Regulatory Evaluation prepared
to accompany the February 1995 final rule establishing that standard,
remains valid.
Regulatory Flexibility Act
NHTSA has also considered the impacts of this final rule under the
Regulatory Flexibility Act. I hereby certify that this rule will not
have a significant economic impact on a substantial number of small
entities. As explained above, today's final rule makes only very minor
changes in the test conditions specified by Standard No. 135, and will
not have any quantifiable impact on testing costs or vehicle costs. For
these reasons, neither manufacturers of passenger cars, nor small
businesses, small organizations or small governmental units which
purchase motor vehicles, will be significantly affected by the rule.
Accordingly, no regulatory flexibility analysis has been prepared.
Paperwork Reduction Act
In accordance with the Paperwork Reduction Act of 1980 (P.L. 96-
511), NHTSA notes that there are no requirements for information
collection associated with this final rule.
National Environmental Policy Act
NHTSA has also analyzed this final rule under the National
Environmental Policy Act and determined that it will not have a
significant impact on the human environment.
Executive Order 12612 (Federalism)
Finally, NHTSA has analyzed this rule in accordance with the
principles and criteria contained in E.O. 12612, and has determined
that this rule will not have significant federalism implications to
warrant the preparation of a Federalism Assessment.
Civil Justice Reform
This final rule does not have any retroactive effect. Under 49
U.S.C. 30103, whenever a Federal motor vehicle safety standard is in
effect, a State may not adopt or maintain a safety standard applicable
to the same aspect of performance which is not identical to the Federal
standard, except to the extent that the State requirement imposes a
higher level of performance and applies only to vehicles procured for
the State's use. 49 U.S.C. 30161 sets forth a procedure for judicial
review of final rules establishing, amending or revoking Federal motor
vehicle safety standards. That section does not require submission of a
petition for reconsideration or other administrative proceedings before
parties may file suit in court.
[[Page 37847]]
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber
products, Tires.
In consideration of the foregoing, 49 CFR Part 571 is amended as
follows:
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
1. The authority citation for Part 571 of Title 49 continues to
read as follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50.
2. Section 571.135 is amended by revising S6.1.1, S6.5.3.3, S7,
S7.1, S7.1.3(a), heading of S7.2.3, S7.2.3(a), S7.2.3(c)(3), S7.2.4(d),
S7.4.3(a), S7.4.3(e), S7.4.4(b), introductory text of S7.4.4(h),
S7.4.5, S7.5.2(a), S7.5.2(c), S7.5.3(a), S7.5.3(b), S7.6.2(a),
S7.6.2(c), S7.6.3, S7.7.3(a), S7.7.3(c), S7.8.2(a), S7.9.2(a),
introductory text of S7.9.3, S7.10.1, S7.10.3(a), S7.10.3(c),
S7.10.3(f), introductory text of S7.10.4, S7.11, S7.11.3(a),
S7.11.3(h), S7.12, S7.12.2(d), S7.13.3(a)(1), S7.13.3(d)(1),
introductory text of S7.14.3(c), S7.14.3(c)(1), S7.14.3(i), S7.15.3(d),
S7.16.3(c), and redesignating S6.5.4.3 as S6.5.4.1 and republishing it,
to read as follows:
Sec. 571.135 Standard No. 135; Passenger car brake systems.
* * * * *
S6.1.1. Ambient temperature. The ambient temperature is any
temperature between 0 deg.C (32 deg.F) and 40 deg.C (104 deg.F).
* * * * *
S6.5.3.3. In the stopping distance formulas given for each
applicable test (such as S0.10V+0.0060V2), S is the
maximum stopping distance in meters, and V is the test speed in km/h.
* * * * *
S6.5.4.1. The vehicle is aligned in the center of the lane at the
start of each brake application. Steering corrections are permitted
during each stop.
* * * * *
S7. Road test procedures and performance requirements. Each vehicle
shall meet all the applicable requirements of this section, when tested
according to the conditions and procedures set forth below and in S6,
in the sequence specified in Table 1:
Table 1.--Road Test Sequence
------------------------------------------------------------------------
Section
Testing order No.
------------------------------------------------------------------------
Vehicle loaded to GVWR:
1 Burnish.................................................. S7.1
2 Wheel lock sequence...................................... S7.2
Vehicle loaded to LLVW:
3 Wheel lock sequence...................................... S7.2
4 ABS performance.......................................... S7.3
5 Torque wheel............................................. S7.4
Vehicle loaded to GVWR:
6 Torque wheel............................................. S7.4
7 Cold effectiveness....................................... S7.5
8 High speed effectiveness................................. S7.6
9 Stops with engine off.................................... S7.7
Vehicle loaded to LLVW:
10 Cold effectiveness...................................... S7.5
11 High speed effectiveness................................ S7.6
12 Failed antilock......................................... S7.8
13 Failed proportioning valve.............................. S7.9
14 Hydraulic circuit failure............................... S7.10
Vehicle loaded to GVWR:
15 Hydraulic circuit failure............................... S7.10
16 Failed antilock......................................... S7.8
17 Failed proportioning valve.............................. S7.9
18 Power brake unit failure................................ S7.11
19 Parking brake........................................... S7.12
20 Heating Snubs........................................... S7.13
21 Hot Performance......................................... S7.14
22 Brake cooling........................................... S7.15
23 Recovery Performance.................................... S7.16
24 Final Inspection........................................ S7.17
------------------------------------------------------------------------
S7.1. Burnish.
* * * * *
S7.1.3. * * *
(a) IBT: 100 deg.C (212 deg.F).
* * * * *
S7.2.3. Test Conditions and Procedures.
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(c) * * *
(3) The pedal is released when the second axle locks, or when the
pedal force reaches 1kN (225 lbs), or 0.1 seconds after first axle
lockup, whichever occurs first.
* * * * *
S7.2.4. * * *
(d) If any one of the three valid runs on any surface results in
neither axle locking (i.e., only one or no wheels locked on each axle)
before a pedal force of 1kN (225 lbs) is reached, the vehicle shall be
tested to the torque wheel procedure.
* * * * *
S7.4.3. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(e) Number of runs: With the vehicle at LLVW, run five stops from a
speed of 100 km/h (62.1 mph) and five stops from a speed of 50 km/h
(31.1 mph), while alternating between the two test speeds after each
stop. With the vehicle at GVWR, repeat the five stops at each test
speed while alternating between the two test speeds.
* * * * *
S7.4.4. * * *
(b) For each brake application under S7.4.3 determine the slope
(brake factor) and pressure axis intercept (brake hold-off pressure) of
the linear least squares equation best describing the measured torque
output at each braked wheel as a function of measured line pressure
applied at the same wheel. Only torque output values obtained from data
collected when the vehicle deceleration is within the range of 0.15g to
0.80g are used in the regression analysis.
* * * * *
(h) Plot f1 and f2 obtained in (g) as a function of z,
for both GVWR and LLVW load conditions. These are the adhesion
utilization curves for the vehicle, which are compared to the
performance requirements in S7.4.5. shown graphically in Figure 2:
* * * * *
S7.4.5. Performance requirements. For all braking ratios between
0.15 and 0.80, each adhesion utilization curve for a rear axle shall be
situated below a line defined by z=0.9k where z is the braking ratio
and k is the PFC.
* * * * *
S7.5.2. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(c) Pedal force: 65N (14.6 lbs), 500N (112.4
lbs).
* * * * *
S7.5.3. * * *
(a) Stopping distance for 100 km/h test speed: 70m (230
ft).
(b) Stopping distance for reduced test speed:
S0.10V+0.0060V\2\.
* * * * *
S7.6.2. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(c) Pedal force: 65N (14.6 lbs), 500N (112.4
lbs).
* * * * *
S7.6.3. Performance requirements.
Stopping distance: S0.10V+0.0067V\2\.
* * * * *
S7.7.3. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(c) Pedal force: 65N (14.6 lbs), 500N (112.4
lbs).
* * * * *
S7.8.2. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
[[Page 37848]]
S7.9.2. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
S7.9.3. Performance requirements. The service brakes on a vehicle
equipped with one or more variable brake proportioning systems, in the
event of any single functional failure in any such system, shall
continue to operate and shall stop the vehicle as specified in
S7.9.3(a) or S7.9.3(b).
* * * * *
S7.10.1. General information. This test is for vehicles
manufactured with or without a split service brake system.
* * * * *
S7.10.3. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(c) Pedal force: 65N (14.6 lbs), 500 N (112.4
lbs).
* * * * *
(f) 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.
* * * * *
S7.10.4. Performance requirements.
For vehicles manufactured with a split service brake system, in the
event of any 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, and after activation of the brake system indicator as
specified in S5.5.1, the remaining portions of the service brake system
shall continue to operate and shall stop the vehicle as specified in
S7.10.4(a) or S7.10.4(b). For 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 and after
activation of the brake system indicator as specified in S5.5.1, the
vehicle shall by operation of the service brake control stop 10 times
consecutively as specified in S7.10.4(a) or S7.10.4(b). Each of the 10
stops shall meet the applicable stopping distance requirement.
* * * * *
S7.11. Brake power unit or brake power assist unit inoperative
(System depleted).
* * * * *
S7.11.3. * * *
(a) IBT: 65 deg.C (149 deg.F), 100 deg.C
(212 deg.F).
* * * * *
(h) If the brake power unit or power assist unit operates in
conjunction with a backup system and the backup system is automatically
activated in the event of a primary power service failure, the backup
system is operative during this test.
* * * * *
S7.12. Parking brake.
* * * * *
S7.12.2. * * *
(d) Parking brake applications: 1 application and up to 2
reapplications, if necessary.
* * * * *
S7.13.3. * * *
(a) * * *
(1) Establish an IBT before the first brake application (snub) of
55 deg.C (131 deg.F), 65 deg.C (149 deg.F).
* * * * *
(d) * * *
(1) Maintain a constant deceleration rate of 3.0 m/s2 (9.8
fps2).
* * * * *
S7.14.3. * * *
(c) Pedal force:
(1) The first stop is done with an average pedal force not greater
than the average pedal force recorded during the shortest GVWR cold
effectiveness stop.
* * * * *
(i) Immediately after completion of the second hot performance
stop, drive 1.5 km (0.93 mi) at 50 km/h (31.1 mph) before the first
cooling stop.
* * * * *
S7.15.3. * * *
(d) Deceleration rate: Maintain a constant deceleration rate of 3.0
m/s2 (9.8 fps2).
* * * * *
S7.16.3. * * *
(c) Pedal force: The average pedal force shall not be greater than
the average pedal force recorded during the shortest GVWR cold
effectiveness stop.
* * * * *
Issued on July 18, 1995.
Ricardo Martinez,
Administrator.
[FR Doc. 95-18106 Filed 7-21-95; 8:45 am]
BILLING CODE 4910-59-P