shall conform to Tire and Rim Association or to the European Tyre and Rim Technical
* 3.8.2 Carrier for space tire assembly. Unless otherwise specified (see 6.2), a. carrier for a
spare wheel or rim and tire assembly shall be installed in a readily accessible location on the
vehicle. Threaded fasteners, when used to secure the spare tire in the carrier, shall be
constructed of or plated with corrosion-resistant material. The carrier design shall enable safe
removal or mounting of a spare wheel assembly using only the tools specified in 3.19. The
carrier shall enable the safe removal and installation of the spare tire assembly from and to the
vehicle and carrier without personnel positioning themselves or any part of their body under the
spare tire assembly.
3.8.4 Spare wheel. When specified (see 6.2), a spare wheel or rim shall be mounted in the
tire carrier. When a spare tire assembly is specified (see 3.8.5), a spare wheel or rim shall be
3.8.5. Spare tire. When specified (see 6.2), an inflated spare tire shall be mounted on the
spare wheel or rim specified in 3.8.4. The spare tire shall be of the same size and tread design
and of the same load range (ply rating) as tires installed on the semitrailer.
* 3.9.1 Brakes. The brakes shall be of the full air internal expanding type and shall conform to
Federal Motor Carrier Safety Regulations 393.40 through 393.43,393.45,393.46, and 393.47.
Brake linings shall be of nonasbestos material. The brake system shall include automatic slack
adjusters, piping, hose connections gladhands, spring loaded dust covers or dummy gladhands
equipped with security chains or cables, air reservoirs with remote control drain, brake chambers,
relay emergency valve, and all other parts and connections required for a complete air brake
system. Gladhands shall conform to SAE J318. The location of the gladhands shall be as
recommended in SAE J702. All components of the brake system shall be installed in such a
manner as to provide adequate road clearance when traveling over uneven or rough terrain,
including objects liable to strike and cause damage to the brake system components. Slack
adjusters and air chambers shall be located above the bottom edge of the axle carrier. No part of
the brake system shall extend below the bottom of wheel rims to insure, in case of a flat tire, that
the weight of the semitrailer will be supported by the rim and the flat tire and not be imposed on
any component of the braking system.
3.9.2 Parking brake. Spring or air diaphragm mechanical lock type parking brakes shall be
provided. The parking brakes shall be automatically applied upon disconnection of the
emergency air line and under emergency braking conditions. The parking brakes shall remain in