For instructions, see Group 42 of the
School Bus Chassis Workshop Manual
.
5.5
If removed, install the pawl, pawl spring,
gasket, and pressure-relief capscrew.
Tighten the capscrew 15 to 20 lbf·ft (20 to
27 N·m). Or, remove the screwdriver from
the pull-pawl assembly (if so equipped).
42–06 Bendix Hydro-Max
®
Power Booster Checking
Check for proper operation; for instructions, see
Group 42 of the
School Bus Chassis Workshop
Manual
.
42–07 Brake Lines Checking,
Hydraulic Disc Brakes
Check all hydraulic lines and fittings for damage,
leakage, or looseness.
Replace damaged or leaking components, and
tighten loose fittings.
42–08 Brake Lining Wear
Checking, Hydraulic
Disc Brakes
Before checking lining wear with the wheel removed,
review the following brake lining exposure warnings.
WARNING
Breathing brake lining dust (asbestos or non-
asbestos) could cause lung cancer or lung dis-
ease. Unless exposure can be reduced below legal
limits, wear an air purifying respirator approved
by MSHA or NIOSH at all times when servicing the
brakes, starting with removal of the wheels and
continuing through assembly. To reduce asbestos
exposure below legal limits, apply one of the fol-
lowing methods: (1) An enclosed-cylinder vacuum
system equipped with a High Efficiency Particu-
late Air (HEPA) filter; (2) A solvent spray system
that keeps the asbestos-contaminated parts wet
until they can be placed in a sealed and labelled
plastic bag.
To minimize the possibility of creating airborne brake
lining dust, clean the dust from the brake rotor, brake
caliper, and brake assembly, using an industrial-type
vacuum cleaner equipped with a high-efficiency filter
system. Then, using a rag soaked in water and
wrung until nearly dry, remove any remaining dust.
Do not use compressed air or dry brushing to clean
the brake assembly.
1.
Check lining wear.
1.1
Apply the parking brake. Chock the tires
to prevent vehicle movement.
1.2
Remove one or more of the lining inspec-
tion plugs, and measure brake lining
thickness.
1.3
On front and rear axles, replace linings
worn to less than 1/16 inch (1.6 mm).
1.4
Make sure that the brake rotor and linings
are free of oil and grease.
1.5
Install the inspection plug(s).
2.
If the wheel and hub assembly is removed from
the axle, check lining wear. Replace the linings
on all brake assemblies if worn to less than 1/16
inch (1.6 mm) at the thinnest point.
NOTE: To replace the brake linings, see the ap-
plicable brake section in Group 42 of the
School Bus Chassis Workshop Manual.
42–09 Camshaft Bracket
Bushing Lubricating
Pump multipurpose chassis grease (NLGI grade 1 or
2) into the chamber bracket until it appears at the
slack adjuster end of the bracket. See
. Use
care that no grease enters the drum cavity. If grease
leaks out under the camhead, the camshaft grease
seal is worn or damaged, or is installed backwards.
NOTE: The use of meter-type fittings, having a
maximum 40 psi (275 kPa) pressure relief at
shutoff, is recommended.
Brakes
42
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