[Federal Register Volume 72, Number 194 (Tuesday, October 9, 2007)]
[Rules and Regulations]
[Pages 57450-57458]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-19467]



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Part IV





Department of Transportation





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National Highway Traffic Safety Administration



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49 CFR Part 571



 Federal Motor Vehicle Safety Standards; Brake Hoses; Final Rule and 
Proposed Rule

  Federal Register / Vol. 72, No. 194 / Tuesday, October 9, 2007 / 
Rules and Regulations  

[[Page 57450]]


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DEPARTMENT OF TRANSPORTATION

 National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2007-29349]
RIN 2127-AK01


Federal Motor Vehicle Safety Standards; Brake Hoses

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

ACTION: Final rule; technical amendments; response to petitions.

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SUMMARY: This document, together with a companion notice of proposed 
rulemaking (NPRM) published in today's edition of the Federal Register, 
responds to petitions for reconsideration of a December 2004 final rule 
that updated the Federal motor vehicle safety standard on brake hoses, 
and to a related petition for rulemaking. In that rule, we incorporated 
updated versions of substantive specifications of several Society of 
Automotive Engineers (SAE) Recommended Practices relating to hydraulic 
brake hoses, vacuum brake hoses, air brake hoses, plastic air brake 
tubing, and end fittings.
    In this document, we deny several of the petitions and explain why. 
We also correct typographical errors in, and inadvertent omissions 
from, the December 20, 2004 final rule.
    In the companion NPRM, we respond to additional issues raised in 
the petitions, and propose a number of amendments to the brake hose 
rule in response to the petitions.

DATES: Effective date: This final rule becomes effective December 21, 
2007.
    Compliance date: Optional early compliance is permitted as of 
October 9, 2007.
    Comments: Any petitions for reconsideration of today's final rule 
must be received by NHTSA not later than November 23, 2007.

ADDRESSES: Petitions for reconsideration should refer to the docket 
number for this action and be submitted to: Administrator, National 
Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE., 
Washington, DC 20590, with a copy to DOT Docket Operations, U.S. 
Department of Transportation, Rm. W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590. Please see the Privacy Act heading under 
Rulemaking Analyses and Notices.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, Mr. Jeff Woods, 
Vehicle Dynamics Division, Office of Vehicle Safety Standards 
(Telephone: 202-366-6206) (Fax: 202-366-4921).
    For legal issues, Ms. Dorothy Nakama, Office of the Chief Counsel 
(Telephone: 202-366-2992) (Fax: 202-366-3820).
    You may send mail to both of these officials at: National Highway 
Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, 
DC 20590.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Background
II. Final Rule of December 20, 2004
III. Petitions
IV. Issues Raised by Petitioners and NHTSA's Responses
    A. Hydraulic Brake Hoses
    1. Expansion and Burst Strength (Volumetric Expansion) Test
    B. Plastic Air Brake Tubing
    1. General
    2. Specifying Plastic v. Nylon
    3. Resistance to Battery Acid
    4. High Temperature Burst Strength Test
    5. High Temperature Conditioning, Low Temperature Impact 
Resistance Test
    6. Adhesion Test
    7. Long Term High Temperature Conditioning and Moisture 
Absorption Test
V. Listing and Description of Corrections
VI. Statutory Bases for the Final Rule
VII. Effective Date
VIII. Rulemaking Analyses and Notices
Final Rule Regulatory Text

I. Background

    On October 30, 1998, a joint petition for rulemaking was filed by 
Elf Atochem North America, Inc., Mark IV Industrial/Dayco Eastman, and 
Parker Hannifin Corporation, three brake hose manufacturers. The 
petitioners petitioned for certain requirements relating to brake 
hoses, brake hose tubing, and brake hose end fittings administered by 
the Federal Motor Carrier Safety Administration (FMCSA) to be 
incorporated into the brake hose standard that is currently 
administered by the National Highway Traffic Safety Administration 
(``NHTSA'' or the ``agency''). Specifically, the petitioners sought 
incorporation of the requirements in section 393.45 (Brake tubing and 
hose, adequacy) and section 393.46 (Brake tubing and hose connections) 
of the Federal Motor Carrier Safety Regulations (FMCSR) into section 
571.106 (Brake hoses) of the Federal motor vehicle safety standards 
(``FMVSS''). The petition requested that the application of these SAE 
specifications be limited to hose, tubing, and fittings used on trucks, 
truck-trailer combinations, and buses with either a GVWR greater than 
10,000 lbs. or which are designed to transport 16 or more people, 
including the driver. In addition, the petitioners requested that the 
current versions of the SAE specifications be adopted instead of the 
older versions cited in the FMCSRs.
    NHTSA granted the joint petition for rulemaking, and published a 
notice of proposed rulemaking on May 15, 2003 (68 FR 26384, DOT Docket 
No. 03-14483). The agency agreed with the petitioners that there was a 
safety need to transfer the brake hose, tubing, and fitting 
requirements currently contained in sections 393.45 and 393.46 of the 
FMCSRs to FMVSS No. 106, before the FMCSA removes those requirements. 
NHTSA tentatively concluded that to ensure the continued safety of 
commercial motor vehicle braking systems, the substantive 
specifications of the SAE Recommended Practices should be incorporated 
into FMVSS No. 106, with a few exceptions as noted. This would involve, 
among other changes, establishing a new category in the standard for 
plastic air brake tubing, end fittings, and tubing assemblies.
    NHTSA's decision to grant the joint petition was also based on the 
fact that FMVSS No. 106 had not been substantially updated in many 
years. Revisions over the past 20 years primarily addressed labeling 
issues, inclusion of metric-sized brake hoses, updating test fluids to 
match advances in industry, and minor regulatory revisions to 
individual test conditions such as the whip test and the adhesion test. 
We noted that most of the substantive requirements in Standard 106, 
other than the labeling requirements, were originally based on SAE 
standards and American Society for Testing and Materials (ASTM) 
standards referenced therein. While the SAE and ASTM standards have 
been modified over time to keep pace with technological developments in 
the industry, the substantive requirements of FMVSS No. 106 have 
remained relatively unchanged. NHTSA's proposed changes to Standard No. 
106 intended to take into account the substantial technological 
developments that have occurred. Incorporating many of the SAE 
standards' performance requirements is consistent with Office of 
Management and Budget (OMB) Circular A-119, which directs federal 
agencies to use and/or develop voluntary consensus industry standards, 
in accordance with Pub. L. 104-113, the ``National Technology Transfer 
and Advancement Act of 1995.''

II. Final Rule of December 20, 2004

    On December 20, 2004 (69 FR 76298, DOT Docket No. NHTSA-2003-
14483), NHTSA published a final rule amending the brake hose standard. 
The agency's

[[Page 57451]]

rule differed in the following respects from that petitioned for by the 
petitioners--
    First, instead of simply incorporating complete SAE standards by 
reference as the FMCSRs currently do, NHTSA incorporated only the 
specific requirements/specifications of the SAE standards that are 
either more rigorous than those in Standard No. 106 or are not present 
at all in FMVSS No. 106.
    Second, the agency did not limit the application of those SAE 
requirements/specifications to brake hose, tubing, and fittings used on 
commercial motor vehicles, but made them applicable to all motor 
vehicles. NHTSA determined that all brake hose, tubing, and fittings 
can and should meet the requirements/specifications, regardless of 
their end use.
    Third, although NHTSA agreed with the petitioners that changes to 
FMVSS No. 106 should be based on the most recent versions of the SAE 
standards, instead of the older versions cited in the FMCSRs, the 
agency noted that a number of SAE's standards have been updated since 
the joint petition was filed (in 1998). Accordingly, NHTSA relied on 
what it believed to be the most recent versions of the SAE standards.
    Fourth, the agency did not incorporate SAE standards relating to 
copper tubing, galvanized steel pipe, or end fittings used with 
metallic or non-metallic tubing, materials that are occasionally used 
in chassis plumbing. Since these products are not considered to be 
brake hoses, NHTSA determined them not to be appropriate to include in 
FMVSS No. 106, a brake hose standard.
    Fifth, NHTSA did not incorporate the material and construction 
specifications for Type A and Type B tubing contained in SAE J844, 
Nonmetallic Air Brake System Tubing, and SAE J1394, Metric Nonmetallic 
Air Brake System Tubing because the agency tentatively concluded that 
incorporating those material specifications would be design-
restrictive.
    Sixth, NHTSA did not incorporate the manufacturer identification 
requirements in SAE J1401, Hydraulic Brake Hose Assemblies for Use with 
Nonpetroleum-Base Hydraulic Fluids, because it concluded that the 
manufacturer identification requirements already present in FMVSS No. 
106 are sufficient.

III. Petitions

    In early 2005, NHTSA received petitions for reconsideration of the 
December 20, 2004 final rule from Cooper Standard Automotive (Fluid 
Division), Degussa Corporation, George Apgar Consulting, MPC, Inc., and 
Parker Hannifin Corporation (with separate submissions from its Brass 
Division and from its Hose Products Division). In July 2005, Arkema, 
Inc., submitted a document styled as a petition for reconsideration. 
NHTSA is treating the document as a petition for rulemaking instead 
since its regulations (49 CFR 553.35(a)) provide that a document styled 
as a petition for reconsideration of a final rule and received by the 
agency more than 45 days after the issuance of that final rule will be 
treated as a petition for rulemaking. The petitions addressed a wide 
range of FMVSS No. 106 subjects.
    In this document, we deny several of the petitions and explain why. 
We also correct typographical errors in, and inadvertent omissions 
from, the December 20, 2004 final rule. In a companion NPRM published 
in today's edition of the Federal Register, we respond to additional 
issues raised in the petitions, and propose a number of amendments to 
the brake hose rule in response to the petitions.

IV. Issues Raised by Petitioners and NHTSA's Responses

A. Hydraulic Brake Hoses

    1. Expansion and Burst Strength (Volumetric Expansion) Test--Before 
the final rule was issued, expansion tests were conducted at 1,000 and 
1,500 psi. In the final rule, NHTSA added a 2,900 psi expansion test in 
order to align FMVSS No. 106 with the latest revision of SAE J1401, 
Road Vehicle-Hydraulic Brake Hose Assemblies for Use with Nonpetroleum-
Base Hydraulic Fluids, and incorporated the revised hydraulic expansion 
requirements in Table I--Maximum Expansion of Free Length Brake Hose 
(69 FR 76322). The inside diameter of the hoses listed in the first 
column of Table I are: \1/8\ inch, or 3mm or less; \3/16\ inch or 4-5 
mm and \1/4\ inch or 6 mm or more.
    In a request for an interpretation, Eaton Corporation asked for 
clarification of the set of measurements to use from Table I if the 
inside diameter of a hydraulic brake hose is greater than \1/8\ inch 
but less than \3/16\ inch. In a letter dated January 26, 2005, NHTSA 
explained that the expansion requirements for the \3/16\ inch brake 
hose apply to a brake hose that is larger than \1/8\ inch but smaller 
than \3/16\ inch: ``In other words, the set covers brake hose with 
inside diameter greater than `\1/8\ inch or 3mm' and less than `\1/4\ 
inch or 6 mm.' Thus, the inside diameter of your hydraulic brake hose 
falls into the category described in Table 1 as `\3/16\ inch or 4 to 5 
mm.' ''
    In this final rule, NHTSA will make explicit the principle 
explained in the January 26, 2005 final rule by amending the 
identifying row titles in the first column of Table 1. The inside 
diameters will now be identified as: ``\1/8\ inch, or 3 mm, or less''; 
``> [greater than] \1/8\ inch or 3 mm, to \3/16\ inch, or 5 mm''; and 
``> \3/16\ inch or 5 mm.'' Thus, after the changes, it will be evident 
that hydraulic brake hoses with inside diameters greater than \1/8\ 
inch but less than \3/16\ inch fall into the category described in 
Table I as ``> 1/8 inch or 3 mm, to \3/16\ inch, or 5 mm.''

B. Plastic Air Brake Tubing

    1. General--In response to plastic air brake tubing requirements in 
the final rule, we received requests from four companies. Each of them 
(Degussa, Parker Brass Division, Apgar, and Arkema) stated that because 
the agency did not include a requirement that plastic air brake tubing 
be constructed of nylon (polyamide), there are risks that alternate 
materials will not provide adequate long-term service in air brake 
systems. In addition, Arkema petitioned for inclusion of other tests; a 
battery acid resistance test requirement for copolyester tubing; a high 
temperature burst strength test; an increase in the length of time for 
the high temperature conditioning test from 72 hours to 1,000 hours; a 
quantitative adhesion test (also petitioned for by Degussa); and an 
increase in the length of time for the long-term high temperature 
conditioning and moisture absorption test from 100 hours to 720 hours. 
As explained below, NHTSA has decided it will not make any of these 
additions to test procedures applicable to plastic air brake tubing.
    2. Specifying Plastic v. Nylon--In the December 2004 final rule, 
the agency adopted the generic term ``plastic'' for air brake tubing, 
rather than specify that air brake tubing must be constructed from 
``nylon.'' As discussed in the final rule, the agency did not intend 
restrictions in FMVSS No. 106 for material that may be used to 
manufacture air brake tubing (69 FR 76306). The agency stated that it 
was adopting 22 performance test requirements (one of these is a 
dimensional specification of the tubing) to ensure the safety of 
plastic air brake tubing.
    Apgar stated that removing material requirements from standards and 
regulations is an excellent goal to promote innovation, but makes 
standards development more difficult because the known properties of 
specific materials cannot be taken for granted when the material is not

[[Page 57452]]

specified. Apgar stated that in the absence of specifying polyamide as 
the material for air brake tubing, more requirements than those in the 
agency's final rule are needed. Apgar stated that there is an ongoing 
activity by an SAE subcommittee to develop a standard designated as SAE 
J2547 to describe requirements for alternate construction air brake 
tubing, but that this standard is still a working document.
    Degussa stated that the 22 requirements for plastic air brake 
tubing adopted in the agency's final rule will not guarantee that the 
tubing material will provide safe service for air brake systems. It 
stated that none of the requirements in FMVSS No. 106 or in SAE J844 
reflects long-term field use, and that many of the requirements are 
specific to nylon materials and do not cover potential deficiencies of 
new materials without a proven track record. Degussa cited SAE J2260, 
Nonmetallic Fuel System Tubing, with One or More Layers, that requires 
a 5,000-hour fuel exposure at 60 degrees Celsius and heat aging for 
1,000 hours at 90 degrees Celsius before tests are conducted. It 
further stated that nylons used in air brake tubing have a successful 
track record of many years, but that for new materials, neither the 
requirements of SAE J844 nor the requirements in the FMVSS No. 106 
final rule are sufficient. Degussa proposed that a statement be added 
that materials used for air brake tubing must demonstrate a track 
record over several years, or meet long term test requirements agreed 
upon between material supplier, tubing manufacturer, and end user.
    Parker stated its belief that compared to the then-existing rule, 
the agency's December 20, 2004 final rule compromises vehicle safety, 
and that the new requirements are less practicable than the previous 
requirements in FMVSS No. 106, because the agency did not specify nylon 
for air brake tubing. Parker believes that the burden of compliance 
will shift from the brake tubing component manufacturers to the 
assemblers of air brake tubing assemblies, and that the DOT markings on 
tubing and end fittings will no longer assure that these components are 
compatible.
    Parker stated that numerous entities, including service shops, may 
have to acquire testing capability for the assemblies made with 
alternate tubing materials and the agency did not consider costs of 
such testing capability. Parker stated that the chance of tubing 
assemblies being put into service that do not meet the requirements of 
the FMVSS No. 106 final rule is significant. Parker stated that it 
knows of non-polyamide materials for tubing that can meet the 
requirements of the final rule for tubing, but when made into 
assemblies they do not meet the requirements of the final rule. Parker 
provided no examples of its assertions. A brake hose assembly that does 
not meet the December 20, 2004 final rule (when it takes effect) would 
be in noncompliance. A noncompliant assembly would not be permitted on 
a motor vehicle.
    Arkema stated that the strong safety record of polyamides is well 
established, but it is impossible to foresee what testing will be 
required upon introduction of countless unknown materials and 
constructions. It stated that similar challenges were met by the 
International Standards Organization (ISO) TC22 SC2 Working Group that 
developed ISO 7628, a standard for plastic air brake tubing that allows 
some flexibility of composition of the material used in the 
construction of the tubing. Arkema also mentioned the efforts to 
develop SAE J2547 but acknowledged that this SAE standard is still a 
working document. Arkema asked that a list of all approved materials 
and constructions for the manufacture of nonmetallic air brake tubing 
be established, and that manufacturers of such alternate materials or 
constructions apply for approval from either the agency or from the 
SAE. Arkema asked that the optional early compliance provision in the 
final rule (that manufacturers may meet the new FMVSS No. 106 
requirements starting on February 18, 2005) be rescinded until its 
requested changes to the final rule are made.
    Arkema also stated that tubing made from materials that are more 
elastomeric (rubbery) than polyamide will probably require fittings 
designed especially for that tubing. Arkema asked for adoption of 
several new requirements for plastic air brake tubing including an 
adhesion test for tubing with multi-layer construction; a chemical 
resistance test for each layer of multi-layer tubing; a high-
temperature burst test (similar to that specified in Deutsches 
Instit[uuml]t f[uuml]r Normung e.V. (DIN) 73378); \1\ increasing the 
time of conditioning for the heat aging requirement at S12.11 of FMVSS 
No. 106 from 72 hours to 1,000 hours; checking the effects of moisture 
conditioning and hydrolysis on the mechanical performance of 
alternative materials; and requiring that all currently available SAE 
J246 and J2494 fittings function correctly with any DOT 106-marked air 
brake tubing.
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    \1\ NHTSA notes that DIN 73378 (February 1996) at Section 1 
Scope states in the English translation: ``This standard specifies 
requirements for and methods of testing polyamide tubing intended 
for the transport of fuel in motor vehicles * * *'' Searching on the 
DIN Web site, we were unable to find a DIN standard for polyamide 
air brake hose, other than DIN 74323 that covers coiled tubing only. 
No DIN standard was found for straight air brake tubing used on 
motor vehicles.
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    We have reviewed the requests and note that in many instances they 
are similar to the comments submitted by the same commenters in 
response to the NRPM. The issue of specifying the generic term 
``plastic'' versus specifying ``nylon'' was discussed in the final rule 
(69 FR 76306). The agency determined that it would not be appropriate 
for FMVSS No. 106 to be design-restrictive regarding the material or 
construction methods for air brake tubing, but the standard should be 
performance based to the extent practicable. Arkema's suggestion that a 
list of approved materials and constructions for plastic air brake 
tubing be established and that manufacturers of alternate materials or 
constructions apply for approval from either the agency or the SAE, 
does not meet 49 U.S.C. Section 30115 Certification of Compliance that 
specifies self-certification by each manufacturer of motor vehicles and 
motor vehicle equipment.
    Specifying nylon as the sole construction material for plastic air 
brake tubing would not permit alternate materials that can provide safe 
and satisfactory performance when used in air brake systems. Arkema's 
comments tacitly recognize this in Arkema's statement that use of new 
materials and constructions will allow innovation, and will perhaps 
lead to improved performance and economy. Therefore, the agency will 
consider only the issue of establishing appropriate minimum performance 
requirements to ensure the safety of plastic air brake tubing.
    Parker and Arkema suggested that because the agency did not specify 
nylon as the sole material for plastic air brake tubing in the final 
rule, it was their belief that air brake tubing and end fittings may no 
longer work together. Parker stated that nylon provides a certain level 
of hardness and compressive strength that enables end fittings to 
retain the tubing. These companies also stated that there are non-nylon 
tubing materials that can meet the new FMVSS No. 106 requirements for 
the tubing, but will not retain the end fittings. The agency believes 
that if this were the case, such tubing would be non-compliant with the 
end fitting retention and performance requirements of air brake tubing 
assemblies in FMVSS No. 106 (S11.3.17 through S11.3.24) when the 
December 20, 2004 final rule takes effect. At such

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time, the tubing and/or the assembly would be subject to the agency's 
remedial actions for such non-compliance. Although the agency is not 
able to analyze hypothetical non-compliance situations, it does not 
agree that the burden of compliance has changed from the prior 
requirements under FMVSS No. 106 solely because nylon is not specified 
as the only material that can be used for air brake tubing.
    In the future, if different types of air brake tubing are developed 
that require unique end fittings, additional rulemaking may be required 
to differentiate (by labeling or other means) the various types of 
tubing and end fittings. This is the approach currently taken in FMVSS 
No. 106 for rubber air brake hoses that are designated as Types A, AI, 
and AII (and now a Type AIII petitioned for addition by Gates 
Corporation), that each have unique dimensions and corresponding end 
fittings.
    3. Resistance to Battery Acid--Apgar's petition for reconsideration 
requested that the agency include the battery acid resistance test from 
ISO 7628-2 in FMVSS No. 106. ISO 7628-2 includes a battery acid 
resistance test requirement for copolyester brake tubing. (See Section 
7.11 of ISO 7628-2.) The ISO test requires that three samples of tubing 
be bent around a test cylinder with a radius of five times the outside 
diameter of the tubing, and then be immersed in a sulfuric acid 
solution at room temperature for 70 hours. After this conditioning, the 
tubing must have no dimensional change greater than two percent, no 
change in weight greater than two percent, nor any evidence of 
cracking.
    In considering whether to propose adopting the ISO 7628-2 
requirement into FMVSS No. 106 to ensure the safety of all types of 
plastic air brake tubing, the agency conducted additional review of SAE 
J844 and found that under Section 1--Scope, the standard states that 
the tubing it applies to is not to be used in an area subject to attack 
by battery acid. In practice, the agency believes that the battery 
installations on heavy vehicles are such that air brake tubing is not 
routed in the vicinity of the batteries, so that exposure to battery 
acid is avoided. There may be other situations (such as transportation 
of new or used lead-acid batteries) in which air brake tubing could be 
exposed to battery acid, but the agency believes that adequate 
environmental and hazardous materials transportation requirements make 
such exposure unlikely to occur. In addition, we note that the issue of 
the need for battery acid resistance for plastic air brake tubing was 
not raised by companies other than Apgar in response to the May 15, 
2003 NPRM on air brake hoses or tubing. For these reasons, the part of 
Apgar's petition asking that FMVSS No. 106 include a battery acid 
resistance test for plastic air brake tubing incorporated from ISO 
7628-2 is denied.
    Arkema's petition requested the addition of several other 
requirements or substantial modifications (all relating to plastic air 
brake tubing) to the current FMVSS No. 106 requirements published in 
the agency's December 2004 final rule. These are described in further 
detail below.
    4. High Temperature Burst Strength Test--Arkema asked that a high 
temperature burst test be added for plastic air brake tubing. Arkema's 
recommended text would specify filling a 12-inch brake hose assembly 
with ASTM IRM 903 oil and conditioning the assembly in air at 100 
degrees Celsius (212 degrees Fahrenheit) for one hour, and then 
increasing the oil pressure inside the assembly at a rate of 3,000 psi 
per minute until burst occurs. The ratio of high temperature burst 
pressure to room temperature burst pressure is then calculated, and the 
required performance would be that the ratio must exceed 37 percent. In 
other words, the burst strength of the tubing at an elevated 
temperature must be greater than 37 percent of the burst strength at 
room temperature.
    Arkema references DIN 73378, Polyamide Tubing for Use in Motor 
Vehicles as the reference standard for calculating this ratio. Arkema 
also provided a table of proposed burst strengths of each size of 
tubing at room temperature and at 100 degrees Celsius. The data in that 
table indicate high temperature to low temperature ratio equal to 40 
percent.
    Degussa recommended that a high temperature burst test from ISO 
7628 be added to FMVSS No. 106 for plastic air brake tubing. The ISO 
test consists of conditioning the tubing in air at 100 degrees Celsius 
(212 degrees Fahrenheit) for 1 hour, and performing a burst strength 
test (pressure increased to failure within 15 to 60 seconds) with the 
tubing at the elevated temperature. The required performance is to 
withstand 2.50 MPa (363 psi) pressure if the tubing is designated as 1 
MPa (145 psi) tubing, or to withstand 3.13 MPa (454 psi) pressure if 
the tubing is designated as 1.25 MPa (181 psi) tubing.
    The agency evaluated the requirements from ISO 7628 to determine 
the ratio of high temperature burst strength to room temperature burst 
strength. For example, the required burst strength for a 1 MPa 
designated tube is 4.00 MPa at room temperature and 2.50 MPa at 100 
degrees Celsius, which yields a ratio of 2.50/4.00 = 0.625 or 63 
percent. This is a much higher ratio than that in the test proposed by 
Arkema, although it appears that the ISO 7628 room temperature burst 
strength requirements (e.g., 4 MPa (580 psi) for 1 MPa type tubing) are 
not particularly stringent in comparison to FMVSS No. 106 requirements 
(e.g., 5.5 MPa (800 psi) to 9.7 MPa (1400 psi) depending on tubing 
size), and even more so considering that trucks in the United States 
are operating at slightly lower air system pressures than European 
trucks.
    Arkema provided a graph of burst pressures for \5/16\ inch 
polyamide tubing over a temperature range of 50 to 275 degrees 
Fahrenheit that shows a considerable decrease in burst strength at 
higher temperatures. The graph shows the burst strength at 200 degrees 
Fahrenheit is approximately 450 psi or 45 percent of the 1,000 psi 
burst strength at 75 degrees Fahrenheit.
    After reviewing Arkema's and Degussa's submissions, we have decided 
that there is no safety need that would be met by adding an additional 
high-temperature test to FMVSS No. 106. Based on requirements in SAE 
J844, the agency adopted a series of high-temperature conditioning 
tests in FMVSS No. 106 at S11.3.2, S11.3.8, S11.3.9, and S11.3.10 that 
use a conditioning temperature of 230 degrees Fahrenheit. Arkema stated 
that plastic air brake tubing may be subjected to intermittent 
temperatures under a vehicle hood as high as 248 degrees Fahrenheit. 
Arkema did not propose any tests be conducted at 248 degrees 
Fahrenheit.
    We believe that vehicle manufacturers are not using plastic air 
brake tubing in high temperature applications because we have not seen 
temperature-related thermoplastic air brake tubing failures on 
vehicles. In a common application of air brake tubing used in the 
engine compartment of heavy trucks, the air brake tubing is routed to 
the treadle valve located on the driver's side of the engine 
compartment while the high-temperature engine exhaust components are 
typically on the passenger's side of the engine compartment.
    In a high-temperature application such as an air compressor 
discharge line, a wire-reinforced elastomeric hose is used rather than 
plastic tubing. It is for these reasons that we believe we have not 
seen instances of plastic tubing failing from high-temperature exposure 
in vehicle applications. We are aware that the 2007 emission-compliant 
heavy

[[Page 57454]]

duty engines could result in higher underhood temperatures.
    We also believe that the SAE Airbrake Tubing and Fittings 
Subcommittee, working with vehicle manufacturers who are installing the 
plastic air brake tubing on their vehicles, would be able to identify 
any need for changes in high-temperature resistance requirements for 
plastic air brake tubing.
    5. High Temperature Conditioning, Low Temperature Impact 
Resistance--Arkema asked that the high-temperature conditioning 
(temperature soak at 230 degrees Fahrenheit) component in S11.3.10 High 
temperature conditioning, low temperature impact resistance of FMVSS 
No. 106, be increased from 72 hours to 1,000 hours. Arkema's 
justification for this request relates to their comment on intermittent 
high underhood temperatures that can reach 248 degrees Fahrenheit 
(measured at the brake tubing) for six minutes or longer upon stopping 
the truck in high ambient temperature conditions. Arkema stated that 
based on a service life of 5 years, with such a hot soak occurring four 
times every twenty-four hours of truck operation, an equivalent of 30 
days of continuous exposure to high temperatures would result.
    The agency does not dispute that brake tubing may see intermittent 
high temperatures in underhood applications, particularly under high 
ambient temperature conditions, but does not conclude that the 
substantial test burden that would result by increasing the S11.3.10 
high temperature soak from 72 hours to 1,000 hours has been shown to be 
necessary to meet a safety issue. The agency does not conclude that 
Arkema has provided sufficient technical justification for such an 
increase in test burden in the absence of an apparent or known safety 
problem. For these reason, the increase of the high temperature 
conditioning component in S11.3.10 of FMVSS No. 106 from 72 hours to 
1,000 hours is denied.
    6. Adhesion Test--Degussa recommended including a quantitative 
adhesion test as described in S7.13 of SAE J2260, Nonmetallic Fuel 
System Tubing with One or More Layers, November 20042. This includes a 
peel test in which a sample of tubing is cut and then separated at the 
layer interface so that a peel test can be conducted on the strength of 
the interface bond. Degussa recommended that a minimum layer adhesion 
of 1 N/mm (5.6 pounds per inch) be achieved using this method.
    Arkema recommended a similar test requirement. However, Arkema's 
suggested procedure would first subject the tubing to one of ten 
required pre-conditionings, including high temperature conditioning, 
boiling water conditioning, moisture conditioning, and ultraviolet 
light conditioning. Arkema's recommended test procedure describes how 
the layers of the tubing are initially separated using a scalpel, then 
additionally separated using pliers and clamped in a tensile testing 
machine for the peel test to be conducted. Arkema recommended a peel 
strength of 1.0 N/mm for an average value with no instantaneous peel 
strength less than 0.5 N/mm.
    We discussed this issue in detail in both the May 2003 NPRM (68 FR 
26400) and the December 2004 final rule (69 FR 76311). In the NPRM, the 
agency proposed an adhesion test after the tubing was subjected to high 
temperature conditioning. In the final rule, the agency decided not to 
include an adhesion test because the industry comments on this issue 
were divergent as to the peel strength that should be required, and 
because the test appeared to be problematic from compliance and 
enforcement standpoints.
    In their petitions, neither Arkema nor Degussa have satisfactorily 
resolved the issues raised in the final rule regarding the adhesion 
tests. An adhesion test for fuel hose may be suitable for testing 
plastic tubing manufactured for fuel hoses where truly different layers 
of materials exist in the tubing for chemical resistance, mechanical 
strength and other factors. The layers in current plastic air brake 
tubing are, to the agency's knowledge, uniform in material and fully 
bonded such that they cannot be readily separated for a peel test. 
Arkema's proposed method of initiating separation of the layers by 
using a scalpel evidences the permanence of the bond in plastic air 
brake hoses. An adhesion test in this situation can ultimately end up 
testing the tensile strength of the brake tubing material rather than 
the strength of its bonds, in particular where a particular layer is 
very thin.
    Furthermore, we believe that Arkema's recommendation for conducting 
ten pre-conditioning tests, each of which would be followed by an 
adhesion test, would be a substantial compliance test burden on the 
brake tubing manufacturers, especially since the agency is not aware of 
any safety problem that has occurred due to poor adhesion 
characteristics being exhibited by plastic air brake tubing. For these 
reasons, we see no safety justification to propose to add Arkema's 
recommended battery of adhesion tests. This portion of Arkema's 
petition is denied. For technical reasons that have been described 
regarding conducting adhesion tests on plastic tubing with high 
interlayer bonding properties, both Arkema's and Degussa's requests to 
add an adhesion test to FMVSS No. 106 for plastic air brake tubing are 
also denied.
    7. Long-Term High Temperature Conditioning and Moisture 
Absorption--Arkema cited regional high humidity environments in the 
United States as a reason that the tubing conditioning in a humid 
environmental chamber in S12.6, Moisture absorption and burst strength, 
paragraph (c) should be increased from 100 hours to 720 hours. Adopting 
Arkema's recommendation would substantially increase the compliance 
test burden without a demonstrated safety need. Arkema's recommendation 
may be based upon the specific performance of Arkema's brake tubing 
product as discussed below in further detail.
    In its petition, Arkema included a graph of the elongation 
properties of polyamide (nylon) tubing that shows a substantial 
decrease in this elongation at approximately 40 days (960 hours) of 
exposure (a comparison material is mentioned but does not appear in the 
graph). The agency questions if this also translates into a 
corresponding decrease in burst strength, and whether plastic air brake 
tubing in service on motor vehicles experiences this level of 
degradation. Also, the agency does not know if the degradation of 
elongation would be mainly a function of exposure to ambient moisture 
in the atmosphere (as stated by Arkema) or to exposure to moisture 
contained within the air brake system. The data do not indicate whether 
the elongation degradation at 960 hours is accompanied by an increase 
in moisture weight gain or if such weight gain exceeds two percent.
    The data provided by Arkema raises many questions. We also note 
that Arkema's proposed 720 hour conditioning is the time just prior to 
when the nylon tubing properties begin to substantially degrade, so it 
would appear the 720 hour value was selected to match the performance 
curve of this particular material. We further note that Arkema's test 
data shows a conditioning temperature of 212 degrees Fahrenheit, which 
is substantially higher than the 75 degree Fahrenheit conditioning 
temperature that is currently specified in FMVSS No. 106 and in SAE 
J844.
    In reviewing Arkema's petition, the agency has once again reviewed 
its decision to not include the moisture weight gain portion from the 
SAE J844 requirements in the final rule. This requirement states that 
after the tubing is conditioned in the environmental chamber at 100 
percent relative

[[Page 57455]]

humidity at room temperature for 100 hours, the weight of the tubing 
sample shall not increase by more than two percent. Such weight gain 
would be caused by the tubing sample absorbing moisture. In its 
petition, Arkema stated that some thermoplastics are very sensitive to 
moisture associated with temperature, leading to degradation of the 
material (hydrolysis). It stated that the material will get brittle and 
lose mechanical strength over time.
    In the final rule, the agency stated that it did not have a basis 
for believing that a weight gain of more than two percent would 
constitute a safety problem. The agency instead included a burst 
strength test at the end of the test sequence as a check of the 
mechanical strength of the tubing after conditioning it in the humid 
environment.
    We once again reviewed the comments submitted in response to the 
May 2003 NPRM and note that Saint-Gobain Performance Plastics objected 
to the weight gain limit as being designed around nylon and that using 
weight gain as a performance metric is not appropriate. DuPont did not 
object to having a weight gain limit but noted that several other tests 
proposed (and subsequently adopted in the final rule) would be 
satisfactory in evaluating the resistance of the tubing to degradation 
from moisture absorption.
    Based upon all of the information we have at this time, the agency 
has again decided not to propose the adoption of a weight gain limit. 
Therefore, the part of Arkema's petition asking for an increase from 
100 to 720 hours in tubing conditioning in a humid environmental 
chamber in paragraph (c) of S 12.6 moisture absorption and burst 
strength is denied.
    Before undertaking further rulemaking on plastic air brake tubing 
moisture absorption and burst strength, we would ask for complete test 
data from Arkema or other manufacturers so that we may review the 
difference in weight gain for different materials of plastic air brake 
tubing subjected to both 100-hour and longer conditioning times. We 
need this information to determine how much moisture various types of 
tubing materials absorb, and if there is a correlation to a degradation 
of tubing mechanical properties such as burst strength.

V. Listing and Description of Corrections

    In addition, the agency has noted typographical errors or omissions 
in the final rule of December 20, 2004. In this final rule document, we 
are making the following corrections:
    1. S6.1.3 Calculation of expansion at 1,000 psi, 1,500 psi, and 
2,900 psi for hydraulic brake hose. Paragraph (b) of this section 
incorrectly states that the pressure increase rate is 1,500 psi per 
minute. The correct rate of 15,000 psi per minute is being restored in 
this corrections notice.
    2. Table III--Air brake hose dimensions. The minimum inside 
diameter for \1/4\ inch inside diameter, Type A air brake hose, is 
shown as 0.277 inches in Table III of the final rule. This is in error 
and the correct dimension is 0.227 inches, consistent with SAE J1402 
(January 2005) Table 1.
    3. S7.3 Test requirements for air brake hose. In the final rule, 
the second sentence of 7.3 states that in addition to the constriction 
requirements in S7.3.1, air brake hose is subject to the requirements 
in S7.3.2 through S7.3.14. This is incorrect because it should cite the 
requirements in S7.3.2 through S7.3.13.
    4. S7.3.5 Ozone resistance for air brake hose. The test temperature 
is specified as 104 degrees Fahrenheit (49 degrees Celsius). The 
correct metric conversion for 104 degrees Fahrenheit is 40 degrees 
Celsius.
    5. S8.7 Flex strength and air pressure test for air brake hose. 
This requirement includes a flex test apparatus figure with several 
specified dimensions. The table accompanying Figure 5 describes the 
dimensions of the test apparatus for various sizes of air brake hose. 
The ninth column specifies the ``C'' dimension of Position ``2'' of the 
test apparatus for a \7/16\, \1/2\, or \5/8\ inside diameter hose and 
is shown as 5.00 inches (102 mm). The correct metric conversion for 
5.00 inches is 127 mm. This correction is being made to the table 
accompanying Figure 5.
    6. S8.12 End fitting corrosion resistance for air brake hose end 
fittings. This section states how to conduct the corrosion test in 
S6.9, using an air brake hose. However, in the final rule S6.9 was 
changed to incorporate a new dynamic ozone resistance test, and the 
corrosion test was moved to S6.11. The correct reference to the 
corrosion resistance test in S6.11 is made to S8.12 in this notice. 
This revision was inadvertently not included in the NPRM or final rule.
    7. S9.1.2 End fittings for vacuum brake hose. The first sentence of 
this section states ``[e]xcept for an end fitting that is attached by 
heat striking or by interference fit * * *'' However, the agency notes 
that the word ``striking'' should be ``shrinking,'' consistent with 
similar text in S9.1.3. Heat shrinking is a process that may be used to 
assemble end fittings onto vacuum brake hose. This typographical error 
is corrected in this notice.
    8. S9.2.1 Constriction test for vacuum brake hose and S10.10 
corrosion resistance for vacuum brake hose. The citation at the end of 
S9.2.1 references the constriction test procedure as S10.10. In the 
December 2004 final rule, S10.10 is the constriction test, however, 
this conflicts with the existing S10.10 in FMVSS No. 106 that is the 
end fitting corrosion resistance test. Therefore, the constriction test 
in the December 2004 final rule is redesignated as S10.11, and the 
reference in S9.2.1 is changed to S10.11 as well.
    We also revise S10.10, corrosion resistance test, to correct a 
revision that was omitted from the final rule. The reference in S10.10 
to ``conduct the test specified in S6.9'' is changed to ``conduct the 
test specified in S6.11'' to reflect changes that were made in S6 in 
the December 2004 final rule.
    9. S9.2.3 Low temperature resistance for vacuum brake hose. 
Paragraph (b) of this section references the hydrostatic pressure test 
as S10.6. This is incorrect, because the hydrostatic pressure test 
procedure is in S10.1(e). The correction is made in this notice.
    10. S10.7 Swell and adhesion test for vacuum brake hose. Paragraph 
(c) of this section states that after soaking a vacuum brake hose in 
reference fuel, the constriction test in S10.10 is to be conducted. 
However, the reference for the constriction test is changed to S10.11 
as described in item 8 above. This change is made in S10.7 as well.
    11. S10.9 Deformation test for vacuum brake hose. S10.9 states that 
Table VI specifies the test specimen dimensions to be used for 
conducting the deformation test. However, the header of the second 
column in Table VI states ``Specimen dimensions (see fig. 4)'' is 
incorrect because Figure 4 was changed to Figure 7 in the December 2004 
final rule. This revision to the header in Table VI is made in this 
final rule.
    12. S11.3 Test requirements for plastic air brake tubing. The final 
rule states that in addition to the constriction requirements in 
S11.3.1, plastic air brake tubing is subject to the requirements in 
S11.3.2 through S11.3.22. This is incorrect. The correct citation is to 
the requirements of S11.3.2 through S11.3.24.
    13. S12.6 Moisture absorption and burst strength for plastic air 
brake tubing. Paragraph (e) of this section has an equation to 
calculate the percentage moisture absorption, but a division symbol is 
missing from the text in the final rule. Paragraph (g) of this section

[[Page 57456]]

is missing the letter ``S'' in reference to S12.5. The corrections to 
both paragraphs (e) and (g) are made in this final rule.
    14. S12.10 High temperature resistance test for plastic air brake 
tubing. The temperature specification for conditioning the tubing is 
230 degrees Fahrenheit. The metric equivalent temperature of 110 
degrees Celsius, missing from the text, is included in this final rule.
    15. S12.15 High temperature conditioning and collapse resistance 
test for plastic air brake tubing. Paragraph (b)(4) of this section 
states to condition the holding device and brake hose in an air oven at 
230 degrees Fahrenheit (110 degrees Celsius) for 24 hours. However, as 
stated in the test requirements in S11.3.14, the correct temperature 
specification is 200 degrees Fahrenheit (93 degrees Celsius).
    Paragraph (c) of this of S12.15 includes an equation to calculate 
the percentage collapse of the outside diameter of the tubing. A 
division symbol missing from the text in the December 20, 2004 final 
rule is included in this final rule.
    16. S12.17 Oil resistance test for plastic air brake tubing. 
Paragraph (b) of this section references ASTM 903 oil. The correct 
reference is ASTM IRM 903 oil.
    17. S12.23 Thermal conditioning and end fitting retention test for 
plastic air brake tubing. Paragraph (a) of this section incorrectly 
references ASTM IBM 903 oil. The correct reference is ASTM IRM 903 oil.

VII. Effective Date

    Because the changes in this final rule are minor ones on the order 
of correcting typographical errors and other inadvertent omissions in 
FMVSS No. 106, this final rule will take effect on December 21, 2007. 
This final rule corrects the final rule of December 20, 2004 (69 FR 
76298), which will take effect on December 20, 2007 (See 71 FR 74823, 
December 13, 2006). Optional early compliance is permitted as of the 
date this document is published in the Federal Register.

VIII. Rulemaking Analyses and Notices

    This rule makes technical corrections and has no impact on the 
regulatory burden of manufacturers. The agency discussed the relevant 
requirements of Executive Order 12866, the Department of 
Transportation's regulatory policies and procedures, the Regulatory 
Flexibility Act, the National Environmental Policy Act, Executive Order 
13132 (Federalism), the Unfunded Mandates Act, Civil Justice Reform, 
the National Technology Transfer and Advancement Act, and the Paperwork 
Reduction Act in the December 2004 final rule cited above. Those 
discussions are not affected by these technical amendments.

Privacy Act

    Please note that anyone is able to search the electronic form of 
all documents received into any of our dockets by the name of the 
individual submitting the document (or signing the document, if 
submitted on behalf of an association, business, labor union, etc.). 
You may review DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (Volume 65, Number 70; Pages 
19477-78).

List of Subjects in 49 CFR Part 571

    Imports, Incorporation by Reference, Motor vehicle safety, Motor 
vehicles, Rubber and rubber products, and Tires.

0
In consideration of the foregoing, NHTSA amends 49 CFR part 571 as 
follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority for part 571 continues to read as follows:

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


0
2. Section 571.106 is amended by:
0
a. Revising Table I;
0
b. Revising paragraph (b) of S6.1.3;
0
c. Revising Table III;
0
d. Revising in S7.3, the second sentence;
0
e. Revising S7.3.5;
0
f. Revising the Table Accompanying Figure 5, following S8.7.1;
0
g. Revising S8.12;
0
h. Revising in S9.1.2, the introductory text;
0
i. Revising S9.2.1;
0
j. Revising in S9.2.3, paragraph (b);
0
k. Revising in S10.7, paragraph (c);
0
l. Revising Table VI following S10.9.2(a);
0
m. Redesignating S10.10 as S10.11;
0
n. Adding new S10.10;
0
o. Revising in S11.3, the second sentence;
0
p. Revising in S12.6, paragraphs (e) and (g);
0
q. Revising in S12.10, the first sentence;
0
r. Revising in S12.15, paragraph (b)(4) and paragraph (c);
0
s. Revising in S12.17, in paragraph (b), the first sentence, and
0
t. Revising in S12.23, paragraph (a).
    The additions and revisions read as follows:


Sec.  571.106  Standard No. 106; Brake hoses.

* * * * *

                          Table I.--Maximum Expansion of Free Length Brake Hose, CC/FT
----------------------------------------------------------------------------------------------------------------
                                                                    Test pressure
                                   -----------------------------------------------------------------------------
                                            1,000 psi                 1,500 psi                 2,900 psi
   Hydraulic brake hose, inside    -----------------------------------------------------------------------------
             diameter                 Regular        Low          Low        Regular      Regular        Low
                                     expansion    expansion    expansion    expansion    expansion    expansion
                                        hose         hose         hose         hose         hose         hose
----------------------------------------------------------------------------------------------------------------
\1/8\ inch, or 3mm, or less.......         0.66         0.33         0.79         0.42         1.21         0.61
> \1/8\ inch or 3mm, to \3/16\             0.86         0.55         1.02         0.72         1.67         0.91
 inch or 5 mm.....................
> \3/16\ inch or 5 mm.............         1.04         0.82         1.30         1.17            *            *
----------------------------------------------------------------------------------------------------------------

* * * * *
    S6.1.3 Calculation of expansion at 1,000 psi, 1,500 psi, and 2,900 
psi.
* * * * *
    (b) Close the valve to the burette, apply pressure at the rate of 
15,000 psi per minute, and seal 1,000 psi in the hose (1,500 psi in the 
second series, and 2,900 psi in the third series).
* * * * *

[[Page 57457]]



   Table III.--Air Brake Hose Dimensions--Inside Diameter (ID) and Outside Diameter (OD) Dimensions in Inches
                                                  (Millimeters)
----------------------------------------------------------------------------------------------------------------
                                                  Type A--Hose Size--Nominal Inside Diameter
                             -----------------------------------------------------------------------------------
                                                                                        \1/2\ SP
                                  \1/4\        \5/16\         \3/8\        \7/16\         \(1)\         \5/8\
----------------------------------------------------------------------------------------------------------------
Min. I.D....................        0.227         0.289         0.352         0.407         0.469         0.594
                                     (5.8)         (7.3)         (8.9)        (10.3)        (11.9)        (15.1)
Max. I.D....................        0.273         0.335         0.398         0.469         0.531         0.656
                                     (6.9)         (8.5)        (10.1)        (11.9)        (13.5)        (16.7)
Min. O.D....................        0.594         0.656         0.719         0.781         0.844         1.031
                                    (15.1)        (16.7)        (18.3)        (19.8)        (21.4)        (26.2)
Max. O.D....................        0.656         0.719         0.781         0.843         0.906         1.094
                                    (16.7)        (18.3)        (19.8)        (21.4)        (23.0)        (27.8)
----------------------------------------------------------------------------------------------------------------
                                               Type AI \(2)\--Hose Size--Nominal Inside Diameter
                             -----------------------------------------------------------------------------------
                                   \3/16\         \1/4\        \5/16\       \13/32\         \1/2\         \5/8\
----------------------------------------------------------------------------------------------------------------
Min. I.D....................        0.188         0.250         0.312         0.406         0.500         0.625
                                     (4.8)         (6.4)         (7.9)        (10.3)        (12.7)        (15.9)
Max. I.D....................        0.214         0.281         0.343         0.437         0.539         0.667
                                     (5.4)         (7.1)         (8.7)        (11.1)        (13.7)        (16.9)
Min. O.D....................        0.472         0.535         0.598         0.714         0.808         0.933
                                    (12.0)        (13.6)        (15.1)        (18.1)        (20.5)        (23.7)
Max. O.D....................        0.510         0.573         0.636         0.760         0.854         0.979
                                    (13.0)        (14.6)        (16.2)        (19.3)        (21.7)        (24.9)
----------------------------------------------------------------------------------------------------------------
                                              Type AII \(2)\--Hose Size--Nominal Inside Diameter
                             -----------------------------------------------------------------------------------
                                   \3/16\         \1/4\        \5/16\       \13/32\         \1/2\         \5/8\
----------------------------------------------------------------------------------------------------------------
Min. I.D....................        0.188         0.250         0.312         0.406         0.500         0.625
                                     (4.8)         (6.4)         (7.9)        (10.3)        (12.7)        (15.9)
Max. I.D....................        0.214         0.281         0.343         0.437         0.539         0.667
                                     (5.4)         (7.1)         (8.7)        (11.1)        (13.7)        (16.9)
Min. O.D....................        0.500         0.562         0.656         0.742         0.898         1.054
                                    (12.7)        (14.3)        (16.7)        (18.8)        (22.8)        (26.8)
Max. O.D....................        0.539         0.602         0.695         0.789         0.945         1.101
                                    (13.7)        (15.3)        (17.7)        (20.1)        (24.0)        (27.9)
----------------------------------------------------------------------------------------------------------------
\(1)\ Notes: Type A, sizes \3/8\, \7/16\, and \1/2\ Special can be assembled with reusable end fittings. All
  sizes can be assembled using permanently-attached (crimped) end fittings.
\(2)\ Types AI and AII, all sizes, can be assembled with reusable or permanently-attached (crimped) end
  fittings.

* * * * *
    S7.3 Test requirements. * * * However, a particular hose assembly 
or appropriate part thereof need not meet further requirements after 
having met the constriction requirement (S7.3.1) and then having been 
subjected to any one of the requirements specified in S7.3.2 through 
S7.3.13.
* * * * *
    S7.3.5 Ozone resistance. An air brake hose assembly shall not show 
cracks visible under 7-power magnification after exposure to ozone for 
70 hours at 104 degrees Fahrenheit (40 degrees Celsius) when bent 
around a test cylinder of the radius specified in Table IV for the size 
of hose tested (S8.4).
* * * * * Q

                                            Table Accompanying Figure 5.--Dimensions in Inches (Millimeters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Dimensions
                                                                         -------------------------------------------------------------------------------
             Free hose length               Nominal hose inside diameter              Position ``1''                          Position ``2''
                                                                         -------------------------------------------------------------------------------
                                                                              A         B         C      R\(1)\       A         B         C      R\(1)\
--------------------------------------------------------------------------------------------------------------------------------------------------------
10.00 (254)...............................  \3/16\, \1/4\...............     3.00      2.75      3.75      1.40      3.00      2.75      3.75      1.20
                                                                              (76)      (70)      (95)      (34)      (76)      (70)      (95)      (30)
11.00 (279)...............................  \5/16\, \3/8\, \13/32\......     3.00      3.50      4.50      1.70      3.00      3.50      4.50      1.30
                                                                              (76)      (89)     (114)      (43)      (76)      (89)     (114)      (33)
14.00 (355)...............................  \7/16\, \1/2\, \5/8\........     3.00      4.00      5.00      2.20      3.00      4.00      5.00      1.80
                                                                              (76)     (102)     (127)      (56)      (76)     (102)     (127)      (46)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note (1): This is an approximate average radius.

* * * * *
    S8.12 End fitting corrosion resistance test. Conduct the test 
specified in S6.11 using an air brake hose assembly.
* * * * *
    S9.1.2 End fittings. Except for an end fitting that is attached by 
heat shrinking or by interference fit with

[[Page 57458]]

plastic vacuum hose or that is attached by deformation of the fitting 
about a hose by crimping or swaging, at least one component of each 
vacuum brake hose fitting shall be etched, embossed, or stamped in 
block capital letters and numerals at least one-sixteenth of an inch 
high with the following information:
* * * * *
    S9.2.1 Constriction. Except for that part of an end fitting which 
does not contain hose, every inside diameter of any section of a vacuum 
brake hose assembly shall not be less than 75 percent of the nominal 
inside diameter of the hose if for heavy duty, or 70 percent of the 
nominal inside diameter of the hose if for light duty (S10.11).
* * * * *
    S9.2.3 Low temperature resistance. * * *
* * * * *
    (b) Not leak when subjected to a hydrostatic pressure test 
(S10.1(e)).
* * * * *
    S10.7 Swell and adhesion test.
* * * * *
    (c) Remove fuel and conduct the constriction test in S10.11.
* * * * *

                   Table VI.--Dimensions of Test Specimen and Feeler Gage For Deformation Test
----------------------------------------------------------------------------------------------------------------
       Hose inside diameter *           Specimen dimensions (see Fig. 7)           Feeler gage dimensions
----------------------------------------------------------------------------------------------------------------
       in.                 mm            Depth (inch)      Length (inch)       Width (inch)     Thickness (inch)
----------------------------------------------------------------------------------------------------------------
         \7/32\                  5             \3/64\                  1              \1/8\             \3/64\
          \1/4\                  6             \1/16\                  1              \1/8\             \1/16\
         \9/32\    .................           \1/16\                  1              \1/8\             \1/16\
        \11/32\                  8             \5/64\                  1             \3/16\             \5/64\
          \3/8\                 10             \3/32\                  1             \3/16\             \3/32\
         \7/16\    .................           \5/64\                  1              \1/4\             \5/64\
        \15/32\    .................           \5/64\                  1              \1/4\             \5/64\
          \1/2\                 12              \1/8\                  1              \1/4\              \1/8\
          \5/8\                 16             \5/32\                  1              \1/4\             \5/32\
          \3/4\    .................           \3/16\                  1              \1/4\             \3/16\
              1    .................            \1/4\                  1              \1/4\              \1/4\
----------------------------------------------------------------------------------------------------------------
*These sizes are listed to provide test values for brake hoses manufactured in these sizes. They do not
  represent conversions.

* * * * *
    S10.10 End fitting corrosion resistance test. Conduct the test 
specified in S6.11 using a vacuum brake hose assembly.
* * * * *
    S11.3 Test requirements. * * * However, a particular tubing 
assembly or appropriate part thereof need not meet further requirements 
after having met the constriction requirement (S11.3.1) and then having 
been subjected to any one of the requirements specified in S11.3.2 
through S11.3.24. * * *
* * * * *
    S12.6 Moisture absorption and burst strength.
* * * * *
    (e) Calculate percentage of moisture absorption as follows:

([Conditioned Weight--Initial Weight] / [Initial Weight]) x 100
* * * * *
    (g) Conduct the burst strength test in S12.5 except use 80 percent 
of the burst strength pressure for the size of tubing being tested as 
specified in Table VIII.
* * * * *
    S12.10 High temperature resistance test. Condition the tubing in an 
air oven at 230 degrees Fahrenheit (110 degrees Celsius) for 72 hours. 
* * *
* * * * *
    S12.15 High temperature conditioning and collapse resistance test.
* * * * *
    (b) Preparation.
* * * * *
    (4) Condition the holding device and tubing in an air oven at 200 
degrees Fahrenheit (93 degrees Celsius) for 24 hours. Remove the 
holding device and tubing and allow to cool at room temperature for 
thirty minutes.
* * * * *
    (c) Calculation. Calculate the percentage collapse of the outside 
diameter of the tubing as follows: ([Initial Outside Diameter--Final 
Outside Diameter] / [Initial Outside Diameter]) x 100
* * * * *
    S12.17 Oil resistance test.
    (b) Immerse the tubing in ASTM IRM 903 oil at 212 degrees 
Fahrenheit (100 degrees Celsius) for 70 hours. * * *
* * * * *
    S12.23 Thermal conditioning and end fitting retention test. (a) 
Apparatus. A source of hydraulic pressure that includes a pressure 
gauge or monitoring system, uses ASTM IRM 903 oil, and is constructed 
so that an air brake tubing assembly mounted to it can be conditioned 
in an environmental test chamber.
* * * * *

    Issued on: September 27, 2007.
Nicole R. Nason,
Administrator.
[FR Doc. E7-19467 Filed 10-5-07; 8:45 am]
BILLING CODE 4910-59-P