3 Troubleshooting and Testing
26
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Troubleshooting
Conditions you may experience, and suggested solutions, appear in
Table D.
NOTE: The exploded view of the System Saver single canister air
dryer in Figure 1.7 illustrates the location of components in the
dryer.
Table D: System Saver Series Air Dryer Troubleshooting
Condition Possible Cause
Conditions May Occur In:
Solution
Regeneration
Style Air
Dryers
Dedicated
Purge Tank
Air Dryers
Dryer leaks from
purge valve during
compressor loaded
cycle. The leak may
cause excessive
compressor cycling
or prevent the
system from
building air
pressure.
Purge valve frozen open (cold
weather operation).
Yes Yes Check heater. Repair/replace if
necessary. Make sure governor to dryer
port 4 line is free of water/oil.
Remove and inspect purge valve and
clean water/oil from top of piston.
Debris under purge valve seat,
such as particles from fittings or
air inlet line.
Yes Yes Disassemble and clean purge valve.
Remove cartridge and clean dryer sump
area.
Purge valve washer installed
upside-down.
Yes Yes Ensure lip on aluminum washer faces
DOWN, away from dryer.
Wrong air line connected to
dryer port 4 (unloader port).
Yes Yes Verify correct air line installation and
correct as needed.
Purge valve snap ring not fully
seated in groove.
Yes Yes Seat snap ring fully into groove.
Regeneration cycle
too long (more than
30 seconds),
accompanied by loss
of pressure in the
supply tank.
Outlet check valve not seating. Yes Yes Inspect and replace outlet check valve
as needed.
Regeneration valve not shutting
off regeneration airflow.
Yes No Replace regeneration valve.