Thomas SAF-T-LINER C2, Руководство по обслуживанию

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42–00 Safety Precautions
Safety Precautions in this section apply to all
procedures within this group.
DANGER
When working on the vehicle, shut down the en-
gine or motor, set the parking brake, and chock
the tires. Before working under the vehicle, always
place jack stands under the frame rails to ensure
the vehicle cannot drop. Failure to follow these
steps could result in serious personal injury or
death.
42–01 Bendix Air Dryer AD–9
or AD–IP Desiccant
Replacing
AD–9 Air Dryer
1. Park the vehicle on a level surface and apply the
parking brake. Shut down the engine. Chock the
tires.
2. Completely drain all air reservoirs. Air pressure
gauges should read 0 psi (0 kPa).
IMPORTANT: The compressor discharge line
may contain residual air pressure.
3. Identify, tag, and disconnect the three air lines
from the end cover.
4. Disconnect the harness connector from the
heater and thermostat assembly.
5. Loosen the bolt that secures the upper mounting
bracket strap.
6. Remove the two bolts that secure the air dryer to
the lower mounting bracket. Mark the position of
the mounting bracket to the end cover and mark
the bolts to ease installation.
7. Remove the upper mounting bracket strap bolt,
and remove the air dryer from the vehicle.
8. Place the air dryer on a bench and remove the
remaining 6 bolts, 12 washers, 6 nuts, and the
air dryer housing. See
Fig. 1 . Discard the nuts.
Remove the end-cover-to-housing O-ring.
9. Clamp the desiccant cartridge in a vise.
WARNING
Clamping the end cover or housing in a vise could
seriously compromise the ability of the air dryer
to hold air pressure, which could cause a failure
in the brake system, resulting in personal injury or
property damage.
10. Twist the end cover counterclockwise to release
the cartridge from the end cover. Rotate the end
cover until it completely separates from the des-
iccant cartridge.
NOTE: A substantial torque, up to 50 lbf·ft (68
N·m), may be necessary to remove the desic-
cant cartridge.
11. Remove and discard desiccant cartridge O-rings.
CAUTION
Dirt or obstructions in the O-ring grooves can
cause an O-ring failure that will result in an air
leak.
12. Lubricate new O-rings with grease supplied in
the kit and install them in the end cover.
13. Install the desiccant cartridge on the end cover.
Turn the cartridge clockwise until the desiccant
cartridge makes contact with the end cover.
14. Place the desiccant cartridge in a vise, and turn
the end cover clockwise an additional 180 to 225
degrees to fully tighten the desiccant cartridge to
the end cover.
NOTE: Desiccant cartridge torque should not
exceed 50 lbf·ft (68 N·m).
15. Place the housing over the desiccant cartridge
and align the mounting holes with the end cover.
16. Install the 6 bolts, 12 washers, and 6 new nuts.
Tighten the bolts in a star pattern 270 to 385
lbf·in (3060 to 4340 N·cm). See
Fig. 2 .
17. Install the air dryer on the lower mounting
bracket. Install the two previously marked bolts,
four washers, and two new nuts. Tighten the two
remaining bolts 270 to 385 lbf·in (3060 to 4340
N·cm). Install the bolt, two washers, and a new
nut in the upper mounting bracket strap. Tighten
the upper mounting bracket strap nut 80 to 120
lbf·in (904 to 1356 N·cm).
Brakes
42
Saf-T-Liner C2 School Bus Maintenance Manual, November 2020
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