MM-34
Revised 11-02
Page 9
Section 2
Troubleshooting & Testing
WARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
Routine Maintenance
To keep your Meritor WABCO air dryer operating efficiently, the following routine maintenance is
recommended.
Maintenance Tips
The Meritor WABCO air dryer will provide years of reliable service, even under adverse operating
conditions. To provide additional protection against the harmful effects of extreme heat or cold, here are
a few helpful tips.
Meritor WABCO air dryer components are installed in the air dryer at the factory and are designed to last
for the life of the dryer. Under some operating conditions, however, a replacement may be required. Refer
to Section 3 for replacement guide instructions.
Interval
Required Action
Weekly.
Ensure dryer purges when compressor unloads.
Weekly, or as recommended by the manufacturer.
Drain purge tank (dedicated purge tank dryers).
Weekly, or as recommended by the manufacturer,
whichever is most frequent.
Check for moisture in the system by opening the
drain cock slowly.
O
Every 2-3 years, or more often depending on usage,
vocation, and condition of compressor.
O
Whenever compressor is rebuilt.
Replace the desiccant cartridge.
Figure 2.1
Dedicated Purge Tank
Optimum mounting location for the dedicated
purge tank is
ABOVE
the air dryer.
Extreme Heat
Make sure the compressor discharge line is
long enough to keep inlet air below 175°F
(80°C). (Refer to Operating Environment
Requirements in Appendix II.)
Extreme Cold
Make sure the air dryer heater is in good
working order by running a heater resistance
test. Refer to Heater Resistance in this section.
Check the line from the governor to port 4 of the
dryer for oil and/or water. Keep this line clean to
help prevent freezing.
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