User's Manual

Symptom: What it may indicate: What you should do:
26
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.
Go to Test 4 on page 30.
See 9.0(f).
Replace air dryer heater.
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.
 If discharge line is restricted:
 By more than 1/16" carbon build up,
replace the discharge line (see Table A,
column 2, on page 18 for recommended
size) and go to Test 3 on page 29.
 By other restrictions (e.g. kinks).
Replace the discharge line. See Table A,
column 2, on page 18 for recommended
size.
 The discharge line must maintain a
constant slope down from the compressor
to the air dryer inlet fi tting to avoid low points
where ice may form and block the fl ow.
If, instead, ice blockages occur at the air
dryer inlet, insulation may be added here,
or if the inlet fi tting is a typical 90 degree
fi tting, it may be changed to a straight or
45 degree fi tting. For more information on
how to help prevent discharge line freeze-
ups, see Bendix Bulletins TCH-008-021
and TCH-008-022 (Appendix B). Shorter
discharge line lengths or insulation may be
required in cold climates.
 Inspect air lines and verify check valves are
operating properly.
 Ensure discharge line is installed into the
inlet of the air dryer and delivery is routed
to the service reservoir.
 Verify relief pressure is 250 psi. Replace if
defective.
 Go to Test 6 on page 30.
 Go to Test 4 on page 30.

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.