Symptom:
What it may indicate:
What you should do:
25
10.0 Air charging
system doesn’t
build air.
(a) Governor malfunction*.
(b) Restricted discharge line.
(c) Air dryer heater malfunction:
exhaust port frozen open.
(d) Compressor malfunction.
ð
Go to Test 4 on page 29.
ð
See 9.0(f).
ð
Replace air dryer heater.
ð
Replace the compressor only after making
certain the preceding conditions do not
exist.
11.0 Compressor
safety valve
releases air
(Compressor
builds too much
air).
(a) Restricted discharge line.
(b) Downstream air brake system
check valves or lines may be
blocked or damaged.
(c) Air dryer lines incorrectly installed.
(d) Compressor safety valve
malfunction.
(e) Compressor unloader mechanism
malfunction.
(f) Governor malfunction.
ð
If discharge line is restricted:
ð
By more than 1/16" carbon build up,
replace the discharge line (see Table A,
column 2, on page 17 for recommended
size) and go to Test 3 on page 28.
ð
By other restrictions (e.g. kinks).
Replace the discharge line. See Table A,
column 2, on page 17 for recommended
size.
ð
The discharge line must maintain a
constant slope down from the compressor
to the air dryer inlet fitting to avoid low
points where ice may form and block the
flow. If, instead, ice blockages occur at the
air dryer inlet, insulation may be added
here, or if the inlet fitting is a typical 90
degree fitting, it may be changed to a
straight or 45 degree fitting. For more
information on how to help prevent discharge
line freeze-ups, see Bendix Bulletins TCH-
08-21 and TCH-08-22 (Appendix B).
Shorter discharge line lengths or insulation
may be required in cold climates.
ð
Inspect air lines and verify check valves
are operating properly.
ð
Ensure discharge line is installed into the
inlet of the air dryer and delivery is routed
to the service reservoir.
ð
Verify relief pressure is 250 psi. Replace
if defective.
ð
Go to Test 6 on page 29.
ð
Go to Test 4 on page 29.
ð
Damaged
discharge
line
shown.
* Note: For the Bendix
®
DuraFlo
™
596
air compressor, not only
the governor, but also the SV-1
™
synchro valve used would
need to be tested. See Bulletin TCH-001-048.
