freightliner 108SD 2021, Driver Manual

Page: 129 / 191

5. Install the wheel assemblies. For instructions,
see
Group 40 of the 108SD and 114SD Work-
shop Manual .
6. Remove the jack stands and lower the vehicle.
Drum Brakes
1. Park the vehicle on a level surface, shut down
the engine, and set the parking brake. Chock the
tires. Once the tires are chocked, release the
parking brake.
WARNING
Manually adjusting an automatic slack adjuster to
bring the pushrod stroke within legal limits is
likely masking a mechanical problem. Adjustment
is not repairing. Before adjusting an automatic
slack adjuster, troubleshoot the foundation brake
system and inspect it for worn or damaged com-
ponents. Improperly maintaining the vehicle brak-
ing system may lead to brake failure, resulting in
property damage, personal injury, or death.
2. With the engine off, and 100 psi (690 kPa) of air
tank pressure, have an assistant apply and hold
an 80 to 90 psi (552 to 621 kPa) brake applica-
tion.
3. Check to see if the colored over-stroke band on
each brake chamber pushrod is exposed.
If a band shows, the stroke is too long. Check
the foundation brake components for wear or
damage, and repair as needed. See
Group 42 of
the 108SD and 114SD Workshop Manual for in-
spection, troubleshooting, and repair procedures.
4. Measure the applied chamber stroke. See
Table 2 for the proper stroke for the type of
chamber being used. If the stroke is too short,
the brakes may drag or will not fully apply. Check
f422655 07/30/2018
A B
1
2
3
4
1
2
3
4
Tighten the fasteners in the order indicated.
A. Left Hand, Bottom View B. Right Hand, Bottom View
Fig. 7, Meritor Radial Mounted Caliper Tightening Pattern
Brakes
42
108SD and 114SD Maintenance Manual, October 2019
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