[Federal Register Volume 61, Number 214 (Monday, November 4, 1996)]
[Proposed Rules]
[Pages 56652-56656]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28228]

[[Page 56652]]



National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. 95-65; Notice 2]
RIN 2127-AF72

Federal Motor Vehicle Safety Standards; Air Brake Systems, 
Devices That Remove Moisture and Contaminants

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation.

ACTION: Notice of proposed rulemaking (NPRM).


SUMMARY: This document proposes to amend Standard No. 121, Air brake 
systems, to require that each air brake-equipped truck, truck tractor, 
and bus be equipped with a means of automatically removing moisture and 
contaminants from the air system. The purpose of this proposal is to 
improve the safety of air-braked vehicles by improving the reliability 
and durability of antilock braking system (ABS) modulator valves and 
pneumatic control valves. This document also proposes to delete the 
requirement for a supply reservoir since its function (i.e., the 
elimination of moisture and contaminants) would be accomplished by the 
addition of such automatic means. Accordingly, the deletion would not 
adversely affect the safety of those vehicles.

DATES: Comments must be received on or before January 3, 1997.

ADDRESSES: Comments should refer to the docket and notice numbers above 
and be submitted to: Docket Section, National Highway Traffic Safety 
Administration, 400 Seventh Street, SW., Washington, DC 20590. Docket 
hours are 9:30 a.m. to 4 p.m., Monday through Friday.

FOR FURTHER INFORMATION CONTACT: For non-legal issues: Mr. Richard 
Carter, Office of Crash Avoidance, National Highway Traffic Safety 
Administration, 400 Seventh Street, SW., Washington DC 20590, (202) 
366-5274. FAX (202) 366-4329.
    For legal issues: Mr. Marvin L. Shaw, NCC-20, Rulemaking Division, 
Office of Chief Counsel, National Highway Traffic Safety 
Administration, 400 Seventh Street, SW., Washington, DC 20590, (202) 


I. Background
    A. Current Regulations
    B. Petition for Rulemaking
    C. Notice Requesting Comments About Devices that Remove 
    D. Comments on the Notice
II. Agency Proposal
    A. General Discussion
    B. Cost Considerations
III. Rulemaking Analyses and Notices
    A. Executive Order 12866 (Regulatory Planning and Review) and 
DOT Regulatory Policies and Procedures
    B. Regulatory Flexibility Act
    C. National Environmental Policy Act
    D. Executive Order 12612 (Federalism)
    E. Civil Justice Reform

I. Background

A. Current Regulations

    Federal Motor Vehicle Safety Standard No. 121, Air Brake Systems, 
requires air-braked vehicles to be equipped with certain equipment, 
including one or more air service reservoir systems from which air is 
delivered to the brake chambers. (See S5.1.2) In addition, 
manufacturers are required to either (1) equip air-braked vehicles with 
an additional supply reservoir 1 between the service reservoir(s) 
and the compressor, or (2) equip each service reservoir with an 
automatic condensate drain valve.2 Both options remove moisture. 
The supply reservoir collects moisture and solid particulate matter 
before it can enter the service reservoir or reservoirs. An automatic 
condensate drain valve automatically removes moisture and certain solid 
contaminants that become trapped in the bottom of a reservoir. 
Regardless of which option is chosen, all air reservoirs must be fitted 
with a condensate drain valve that can be manually operated. 
Accordingly, an automatic condensate drain valve must also be manually 
operable. (see S5.1.2.4 for trucks and buses and S5.2.1.3 for 

    \1\ The colloquial term for a supply reservoir is ``wet'' tank.
    \2\ The colloquial term for an automatic condensate drain valve 
is ``spitter valve.''

    The Federal Motor Carrier Safety Regulations (FMCSRs) require 
drivers of commercial vehicles to inspect specified features on their 
vehicles, including service brake system, prior to driving to ensure 
those features are ``* * * in good working order.'' (49 CFR 392.7) 
However, the FMCSRs do not require that air reservoirs be drained on 
any fixed periodic basis.

B. Petition for Rulemaking

    On July 28, 1994, Domenic F. Coletta, M.D. submitted a petition for 
rulemaking requesting that Standard No. 121 be amended to require a 
condensate drain valve that automatically purges the moisture and 
contaminants from each reservoir tank on air-brake equipped vehicles. 
Dr. Coletta claimed that automatic drain valves would better ensure 
safety than manual valves since drivers frequently fail to remember to 
manually purge moisture and contaminants from reservoirs. The 
petitioner supplied a video showing New Jersey State police purging 
significant amounts of liquid and contaminants from the air reservoirs 
of heavy vehicles during roadside safety inspections.

C. Notice Requesting Comments About Devices That Remove Contaminants

    On July 24, 1995, NHTSA issued a notice requesting information 
about devices that remove moisture and other contaminants from air 
brake systems (60 FR 37864). The agency explained that keeping air 
brake systems clean and dry prevents degraded brake performance and 
valve freezing, which can lead to brake failure. The agency was 
especially concerned about potential problems with antilock brake 
systems (ABS) malfunctioning, since their modulator valves have smaller 
orifices and therefore are more sensitive to contaminants. NHTSA 
explained that certain equipment such as automatic and manual drain 
valves and air dryer systems can keep air brake systems, particularly 
the air reservoirs, dry and free from contaminants. Drain valves purge 
the reservoirs of liquid condensate and contaminants suspended in that 
liquid. Manual drain valves must be opened by a truck driver or 
maintenance person to drain the reservoir. While ideally this should be 
done each morning before the vehicle is started, some drivers do not do 
so. Automatic drain valves periodically drain the reservoir without the 
need for human intervention.
    There are a variety of devices that reduce the amount of moisture 
and other contaminants in an air brake system by cleaning and drying 
the air. Among the most common are desiccant style air dryers and 
``after-cooler'' air dryers. In a typical desiccant style system, the 
incoming air is routed into the bottom end of an air dryer, where a 
large portion of the oil and water mist fall to its bottom. This 
partially cleaned air then goes through an oil separator. Next the air, 
which is still moist with both oil and water vapor, is passed through a 
``drying bed'' of desiccant material that absorbs the remaining 
moisture. These dryers are equipped with an automatic drain valve that 
periodically purges moisture and contaminants from the air system. In 
contrast, in a typical ``after-cooler''

[[Page 56653]]

system, which uses an air cleaner only, not all the moisture is 
removed, since the air is not passed through a drying bed of desiccant 
    NHTSA stated that according to AlliedSignal, over 80 percent of new 
air braked heavy trucks are being built with air dryers and that more 
than 90 percent of the dryers are the desiccant type. Moreover, that 
company predicted that in five years almost all air braked vehicles 
will be equipped with an air cleaning and drying system.
    NHTSA posed several questions about whether it should nevertheless 
initiate rulemaking to require devices to remove moisture and other 
contaminants from air brake systems. These included questions whether 
contaminants in air brake systems cause a significant safety problem, 
whether devices such as automatic drain valves and air dryers are 
effective in removing moisture and contaminants from air brake systems, 
and whether requiring such devices would be cost effective.

D. Comments on the Notice

    NHTSA received 34 comments from vehicle and equipment 
manufacturers, a safety advocacy group (Advocates for Highway and Auto 
Safety) (Advocates), the Truck Manufacturers Association (TMA), the 
Heavy Duty Brake Maintenance Council (HDBMC), the Truck Trailer 
Manufacturers Association (TTMA), the National Truck Equipment 
Association (NTEA), the National School Transportation Association 
(NSTA), the American Trucking Associations (ATA), individual truck 
operators and fleets, Senator Frank R. Lautenberg, the petitioner, and 
numerous private citizens.
    The manufacturers and associations generally stated that a Federal 
requirement was not necessary, claiming that the present use of air 
dryers, and the trend towards their increased use, was sufficient to 
maintain a safe level of performance. ATA, AlliedSignal, NTEA, NSTA, 
Navistar, TTMA, and TMA stated that they had no records of any 
accidents or crashes caused by contaminated air. TMA stated that while 
contaminants in air brake systems can cause reliability problems in 
specific components, they believe contamination does not result in a 
significant safety problem. TMA, Penske Truck Leasing, and ATA stated 
that a desiccant style air dryer with an integral automatic drain valve 
more effectively removes moisture and other contaminants from an air 
brake system than an automatic drain valve by itself. TMA requested 
that instead of a supply reservoir, the agency should allow either an 
automatic drain valve on each service reservoir or a desiccant style 
air dryer. ATA also stated that desiccant air dryers were more 
effective in keeping air in the brake system clean than automatic drain 
valves. That organization stated that ``automatic drain valves have not 
been found to be an effective device for removing contaminants.''
    The petitioner (Dr. Coletta), manufacturers of automatic drain 
valves, Advocates, and a number of private citizens commented that 
significant safety problems result from moisture and contaminants in a 
vehicle's air system. The petitioner stated that it is very important 
to keep the air reservoir system dry and free of contaminants to 
prevent the contamination and deterioration of the brake system, which 
can result in serious safety problems. To support this claim, Dr. 
Coletta referenced a National Transportation Safety Board (NTSB) study 
of 18 heavy vehicle crashes 3 in which NTSB investigated the 
extent to which brake system performance caused or increased the 
severity of heavy vehicle crashes. Inadequate brake system maintenance 
and poor brake adjustment were either the primary or a contributory 
causal factor in most of the crashes investigated. While not 
specifically mentioned as a primary or direct contributory factor to 
these crashes, the NTSB report noted that in 4 of the 18 cases (22 
percent), significant amounts of moisture and sludge were found in the 
air reservoirs, thereby contributing to the overall poor functioning of 
the vehicles' brake system.

    \3\ Heavy Vehicle Air Brake Performance (NTSB/SS-92/01; 1992)

    Dr. Coletta and others stated that the agency should require that 
each service reservoir be equipped with an automatic drain valve 
instead of a manual drain valve, because truck drivers typically do not 
manually drain the reservoirs. They further claimed that air dryers are 
not an effective way to solve the problem of contaminants and moisture 
in air systems, since air dryers do not remove all moisture from the 
system and are difficult to maintain. These commenters also stated that 
truck drivers will not perform the routine maintenance necessary for 
desiccant systems.

II. Agency Proposal

A. General Considerations

    Based on the available information, NHTSA has decided to propose 
amending Standard No. 121 to require that each air brake-equipped 
truck, truck tractor, and bus be equipped with an automatic means of 
removing moisture and contaminants from the air brake system. The term 
``contaminants'' includes, but is not limited to, carbon and other 
particulates, dirt, oil, soot, and sludge. The agency believes that 
removing moisture and contaminants would increase the reliability and 
durability of both ABS and pneumatic control valves of air brake 
systems, thereby increasing the safety of these vehicles. This is so 
because contaminants cause valves to stick, thereby preventing 
sufficient air pressure from being delivered to the brake. The proper 
functioning of ABS valves is especially important since heavy vehicles 
will be required to be equipped with ABS, beginning in March 1997. In 
addition, the proposed requirements would ensure that air supply lines 
are clear and that maximum air reservoir capacity is available to 
drivers when braking.
    NHTSA is proposing to require air braked vehicles to be equipped 
with a means of automatically removing moisture and contaminants from 
the air brake system for the following reasons. First, according to 
NHTSA's extensive fleet study 4 of ABS-equipped heavy vehicles, 
ABS-equipped truck tractors that were also equipped with desiccant-
style air dryers performed better than truck tractors without these air 
dryers. In particular, vehicles with desiccant-style air dryers did not 
experience leaks in their relay valves. Second, the previously 
mentioned NTSB study of heavy vehicle crashes found that in 4 of 18 
cases (22 percent), significant amounts of moisture and contaminants 
were found in the vehicles' air reservoirs. The agency emphasizes that 
while the study is not a statistically representative sampling of all 
heavy vehicle crashes, it suggests that air system contamination may be 
a problem. Third, AlliedSignal recently conducted a voluntary recall 
5 to address freezing relay valves because the valves failed due 
to exposure to solvents and chemicals such as antifreeze and glycol. 
Apparently, some drivers and mechanics attempted to unfreeze the valves 
by pouring antifreeze into the trailer's air supply and control lines.

    \4\ Klusmeyer, L.F., Gray, A.W., Bishop, J.S., and Van Schoiack, 
M. An In-Service Evaluation of the Performance, Reliability, 
Maintainability, and Durability of Antilock Braking Systems (ABSs) 
for Semitrailers, USDOT Report No. HS 808 059, October 1993.
    \5\ Ref. Voluntary Recall No.94-E-027.

    To achieve this rule's objective, i.e., keeping air brake systems 
dry and free of contaminants, NHTSA considered a number of regulatory 
approaches and decided to propose a broad-based

[[Page 56654]]

equipment requirement rather than specifying a specific device, 
detailed design specifications, or general performance requirements. 
This is the same approach the agency used in establishing S5.1.8 which 
requires that ``wear of the service brakes on newly manufactured heavy 
vehicles to be compensated for by means of a system of automatic 
adjustment.'' (57 FR 47793, October 20, 1992). Moreover, the agency 
believes today's proposal is consistent with the agency's desire to 
avoid issuing regulations that are unnecessarily design specific. NHTSA 
is wary of specifying a particular device, an action that might 
preclude the development of new technologies, particularly in light of 
a recent paper 6 by the Society of Automotive Engineers (SAE) that 
discussed a number of devices and methods that can remove moisture and 
other contaminants from compressed air systems. These methods include 
filtration, desiccant absorption, coalescing, centrifugal force, or a 
combination of these processes. The SAE paper stated that the most 
effective device would employ a combination of these processes, 
particularly filtration, coalescing, and desiccant. These devices would 
be permitted by this proposal.

    \6\ Fitzsimmons, D. Synergy in Air Dryers, Multiple-State 
Processes and Application Requirements, SAE Paper No. 952675, 
November, 1995.

    Another device that would be permitted under this proposal is the 
automatic condensate drain valve, the solution suggested in Dr. 
Coletta's petition. These devices eliminate moisture (i.e., liquid 
condensate) and solid contaminants suspended in that liquid that 
collect at the bottom of the supply reservoir.
    NHTSA has decided at this time not to develop a test procedure and 
performance requirements to evaluate the dryness and cleanness of an 
air brake system for several reasons. First, the practicality of 
developing such a test procedure is unclear at this time. To ensure 
that all (or substantially all) contaminants had been removed, it might 
be necessary for the test procedure to assess the performance of the 
entire air system, including all piping and valves. Such a test could 
be expensive, since the piping and valves are very extensive. Moreover, 
it might be necessary to develop different test set-ups to evaluate the 
wide range of air systems. Second, to the agency's knowledge, criteria 
for evaluating the amount of contamination removal do not currently 
exist. Developing such a test procedure and criteria would have been 
too time-consuming.
    For these reasons, NHTSA has decided to propose an equipment 
requirement at this time. Nevertheless, the agency would prefer 
ultimately to establish performance requirements for this equipment. 
Federal law generally requires Federal agencies to use technical 
standards that are developed or adopted by voluntary consensus 
standards bodies when such technical standards are available; see 
section 12(d) of Pub. L. 104-113. The subject of moisture and solid 
contaminant removal from air brake systems appears to present an 
opportunity for NHTSA to adopt consensus performance requirements 
developed by an organization such as the Society of Automotive 
Engineers (SAE). SAE would be performing a service to the public by 
developing such consensus performance requirements, as well as 
permitting a significant savings in resources for the government. NHTSA 
is aware of and has been monitoring the efforts of the SAE to develop a 
Recommended Practice for assessing the amount of airborne moisture and 
solid particulate matter contaminant levels present at the output side 
of the service reservoirs. If the SAE can reach consensus on some 
performance requirements, NHTSA anticipates relying on those consensus 
requirements in its further consideration of this issue.
    NHTSA requests comments on its decision to propose requiring that 
air-braked vehicles be equipped with a means of automatically removing 
moisture and other contaminants rather than proposing a test procedure 
and performance requirements. The agency also invites comments about 
the proposed terminology used to describe the equipment that the 
amendment would require, especially whether various devices would 
comply with the proposal.
    NHTSA has decided to propose deleting the requirement for a supply 
reservoir since the service reservoirs in an air system would be 
equipped with an automatic means of removing moisture and contaminants 
from the air system. The agency believes that removing supply 
reservoirs would not compromise air brake system performance, provided 
that a means of automatically removing moisture and contaminants is 
added. Nevertheless, the agency invites commenters to submit data and 
test results comparing the durability and reliability of air brake 
systems on vehicles that are equipped as follows: those vehicles 
equipped with a supply reservoir but are not equipped with a means for 
automatically removing moisture and contaminants versus those vehicles 
that are not equipped with a supply reservoir but are equipped with a 
means for automatically removing moisture and contaminants. Also, the 
agency requests comments about the likelihood that a purchaser would 
decide not to equip its vehicles with supply reservoirs, if the 
proposed amendment were adopted.
    NHTSA has decided to retain the requirement of S5.1.2.4 that each 
reservoir be fitted with a manual draining capacity. The agency 
believes this capability is needed as a supplemental means of verifying 
that the primary means of automatically removing moisture and 
contaminants is functioning properly. Periodic manual purging checks to 
ascertain that liquids are not collecting in service reservoirs should 
accomplish this function. Automatic condensate drain valves (or an air 
dryer with an automatic drain valve) that can be manually actuated, 
would comply with this requirement.

B. Cost Considerations

    In its notice requesting comments, NHTSA estimated that devices 
that would comply with requirements to keep the air system clean and 
dry could range from $75-$400 per vehicle. The commenters generally 
concurred with these estimates. The agency estimates that the annual 
production of air braked vehicles is approximately 209,000 (148,000 
truck tractors and approximately 61,000 single unit trucks and buses), 
based on its earlier analysis in the Final Regulatory Evaluation for 
the ABS final rule (60 FR 13216, March 10, 1995). NHTSA estimates that 
90 percent of all currently manufactured truck tractors are already 
equipped with a means of automatically removing moisture and 
contaminants and that 75 percent of all single unit trucks and buses 
are so equipped. This proposal would affect the remaining 30,000 
vehicles (14,800 truck tractors + 15,200 single unit vehicles). They 
would need to be equipped with these devices at a total annual cost of 
between $2.25 million to $12 million.
    NHTSA notes that some of these costs might be offset by savings if 
manufacturers choose to eliminate the supply reservoirs from the 
estimated 209,000 air brake equipped truck tractors, trucks and buses 
that are manufactured each year. The amount of these offsetting savings 
could vary appreciably, depending on a number of factors. First, 
removing one of the three air reservoirs could necessitate increasing 
the size of the remaining two service reservoirs to meet the reservoir 
sizing requirements of S. Nevertheless, two larger reservoirs

[[Page 56655]]

would cost less than three reservoirs and their associated piping and 
fittings. The agency estimates that there would be a savings of between 
$10-$75 per vehicle. Second, the extent to which manufacturers and 
heavy vehicle users decide to no longer equip their vehicles with a 
supply reservoir is uncertain.
    Accordingly, for the purposes of this analysis, the agency has 
conservatively assumed that between 0-50 percent of newly manufactured 
air-braked power units would no longer be equipped with supply 
reservoirs. Based on this assumption, the agency estimates that no 
longer equipping vehicles with supply reservoirs would offset the 
proposal's costs by between $0-$7.8 million per year, with a 
conservative estimate being $1 million. The agency invites comments on 
these cost estimates. After reviewing this information, NHTSA will 
factor in these cost savings in assessing the rulemaking's overall 
    Based on applying this $1 million cost savings to the costs 
associated with requiring air-braked vehicles to be equipped with a 
means of automatically removing moisture and contaminants, NHTSA 
estimates that a total cost of $1.25 million to $11 million would be 
incurred to comply with the proposed requirements. In addition, by 
ensuring dry and clean air, today's rulemaking would contribute to more 
fully achieving the anticipated benefits expected from equipping heavy 
vehicles with ABS.
    NHTSA decided not to propose requiring a means of automatically 
removing moisture and contaminants separately on both towing and towed 
units in a combination-unit vehicle. The agency reasoned that since the 
air used on trailers is supplied by the towing unit, having the means 
to automatically remove moisture and contaminants on the towing unit 
would be sufficient to ensure dry and clean air on towed units as well. 
The agency further reasoned that sufficient safety enhancement, 
relative to the costs incurred, would be achieved by specifying such a 
requirement only for the towing unit. The agency estimates that it 
would cost an additional $13.9 million to $74 million per year to equip 
the 186,100 heavy truck trailers that are manufactured each year. The 
agency solicits additional data and comments on its decision not to 
propose requiring that trailers be equipped with a means of 
automatically removing moisture and contaminants.

Rulemaking Analyses and Notices

A. Executive Order 12866 (Regulatory Planning and Review) and DOT 
Regulatory Policies and Procedures

    This notice has not been reviewed under Executive Order 12866. 
NHTSA has considered the impacts of this rulemaking action and 
determined that it is not ``significant'' within the meaning of the 
Department of Transportation's regulatory policies and procedures. The 
agency's Final Economic Assessment of the final rules amending Standard 
No. 105 and Standard No. 121 to require medium and heavy vehicles to be 
equipped with ABS, concluded that the benefits associated with those 
requirements exceeded the costs that would result. The additional costs 
associated with adding a means of automatically removing moisture and 
contaminants to those vehicles that would otherwise not be equipped 
with them, would increase the costs of the ABS rule by 0.2 percent to 
1.7 percent. This small increase does not alter the agency's original 
determination. Based on the discussion above and this consideration, 
NHTSA believes that the impacts are so minimal as not to warrant 
preparation of an additional full regulatory evaluation.

B. Regulatory Flexibility Act

    NHTSA has also considered the effects of this proposal under the 
Regulatory Flexibility Act. I hereby certify that it would not have a 
significant economic impact on a substantial number of small entities. 
Accordingly, the agency has not prepared a preliminary regulatory 
flexibility analysis.
    NHTSA concluded that the March 1995 final rule amending Standard 
No. 121 did not have a significant impact on a substantial number of 
small entities. The agency concluded then that a small number of 
intermediate and final stage manufacturers that are small businesses 
might be affected by the rule, but that the impact would not be 
substantial. That conclusion is equally valid for this proposal, since 
today's proposal addresses the same types of manufacturers as addressed 
in the March 1995 action, and since the costs of this rulemaking are 
much less.

C. National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for the purposes of the 
National Environmental Policy Act of 1969. The agency has determined 
that implementation of this action would not have any significant 
impact on the quality of the human environment. No changes in existing 
production or disposal processes would result.

D. Executive Order 12612 (Federalism)

    NHTSA has analyzed this action under the principles and criteria in 
Executive Order 12612. The agency believes that this rulemaking action 
would not have sufficient Federalism implications to warrant the 
preparation of a Federalism Assessment. No State laws would be 

E. Civil Justice Reform

    This rulemaking would 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 rulemakings 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.

Public Comments

    Interested persons are invited to submit comments on the proposal. 
It is requested but not required that 10 copies be submitted.
    All comments must not exceed 15 pages in length. (49 CFR 553.21). 
Necessary attachments may be appended to these submissions without 
regard to the 15-page limit. This limitation is intended to encourage 
commenters to detail their primary arguments in a concise fashion.
    If a commenter wishes to submit certain information under a claim 
of confidentiality, three copies of the complete submission, including 
purportedly confidential business information, should be submitted to 
the Chief Counsel, NHTSA, at the street address given above, and seven 
copies from which the purportedly confidential information has been 
deleted should be submitted to the Docket Section. A request for 
confidentiality should be accompanied by a cover letter setting forth 
the information specified in the agency's confidential business 
information regulation. 49 CFR part 512.
    All comments received before the close of business on the comment 
closing date indicated above for the proposal will be considered, and 
will be available for examination in the docket

[[Page 56656]]

at the above address both before and after that date. To the extent 
possible, comments filed after the closing date will also be 
considered. Comments received too late for consideration in regard to 
the final rule will be considered as suggestions for further rulemaking 
action. The NHTSA will continue to file relevant information as it 
becomes available in the docket after the closing date, and it is 
recommended that interested persons continue to examine the docket for 
new material.
    Those persons desiring to be notified upon receipt of their 
comments in the rules docket should enclose a self-addressed, stamped 
postcard in the envelope with their comments. Upon receiving the 
comments, the docket supervisor will return the postcard by mail.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles, Rubber and tires.


    In consideration of the foregoing, the agency proposes to amend 
Standard No. 121, Air Brake Systems, in Title 49 of the Code of Federal 
Regulations at Part 571 as follows:


    1. The authority citation for part 571 would continue to read as 

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50

Sec. 571.121  Standard No. 121; Air Brake Systems

    2. Sec. 571.121 would be amended by revising S5.1.2 and by adding a 
new section S5.1.9, which would read as follows:

Sec. 571.121  Standard No. 121; Air Brake Systems

* * * * *
    S5.1.2  Reservoirs. One or more service reservoir systems, from 
which air is delivered to the brake chambers.
* * * * *
    S5.1.9  Contamination Removal. Each truck, truck tractor and bus 
shall be equipped with a means of automatically removing moisture and 
contaminants from the air system.

    Issued on: October 29, 1996.
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.
[FR Doc. 96-28228 Filed 11-1-96; 8:45 am]