8
Appendix V — Temporary Air Dryer Bypass
46
Meritor WABCO
Maintenance Manual 34 (Revised 03-16)
8 Appendix V — Temporary Air Dryer Bypass
Hazard Alert Messages
Read and observe all Warning and Caution hazard alert messages in
this publication. They provide information that can help prevent
serious personal injury, damage to components, or both.
WARNING
To prevent serious eye injury, always wear eye protection
when you perform vehicle maintenance or service.
Park the vehicle on a level surface. Block the wheels to
prevent the vehicle from moving. Support the vehicle with
safety stands. Do not work under a vehicle supported only by
jacks. Jacks can slip and fall over. Serious personal injury and
damage to components can result.
Open drain valves on all reservoirs to remove all pressurized
air from the air system before you disconnect any component.
Pressurized air can cause serious personal injury.
Bypass Procedure
If the air dryer were to malfunction in a way that the air compressor
cannot build up pressure within the system and the air dryer cannot
be immediately repaired, a temporary bypass of the air dryer may be
required. The bypass is a short term remedy only until the vehicle
can make it to a repair facility and either have the air dryer repaired
or replaced. Long term use of the vehicle with the air dryer
bypassed could result in excessive moisture build up in the air
system.
1.
Wear safe eye protection.
2.
Park the vehicle on a level surface. Block the wheels to prevent
the vehicle from moving.
3.
Drain the entire air system. Open all of the drain valves on all of
the reservoirs.
4.
Ensure that all residual pressure has been released and the air
dryer has been drained to 0 psi. Then, remove the air supply
line from the compressor to the inlet port.
5.
Remove the air line from the dryer discharge port.
6.
Install a T-fitting into the discharge port. Figure 8.1.
Figure 8.1
7.
Using the original fittings, reinstall the discharge line in one of
the branches of the T-fitting.
8.
Using the original fittings, install the air supply line into the
remaining T-fitting port.
9.
Charge the system to cut-out pressure and use a soap solution
to test the T-fitting for air leaks. The vehicle may then be
returned to temporary service.
CAUTION
This is a temporary bypass of the air dryer, and full repair of
the unit must be carried out at the earliest opportunity. Long
term use of the vehicle with the air dryer bypassed could
result in excessive moisture build up in the air system.
Drain Air Reservoirs Daily Until Repairs are
Completed
CAUTION
Long term use of the vehicle with the air dryer bypassed could
result in excessive moisture build up in the air system.
Once the air dryer is removed, contaminants will enter the air
system. Therefore, you will need to manually drain the reservoirs
daily until the repairs are completed.
1.
At end of each working day, park the vehicle and slowly drain
pressure through the drain valves. Leave the valves open to the
atmosphere for several hours if possible.
2.
When repairs are completed, be sure to check that all
reservoirs (including the air dryer) are emptied of all
contaminants.
Figure 8.1
400
9
783
a
T-FITTING
Summary of Contents for 1200E
Page 4: ...Notes...
