Bendix Commercial Vehicle Systems 720CC COMPRESSOR - Manual (Page 27)

A-13
Symptom: What it may indicate: What you should do:
This guide attempts to cover most com-
pressor system problems. Here are some
rare sources of problems not covered in
this guide:
• Turbocharger leakage. Lubricating
oil from leaking turbocharger seals can
enter the air compressor intake and give
misleading symptoms. • Where a compressor does not have
a safety valve installed, if a partial or
complete discharge line blockage has
occurred, damage can occur to the con-
necting rod bearings. Damage of this kind
may not be detected and could lead to
compressor problems at a later date.
17.0 Compressor
leaks coolant (a) Improperly installed plugs or coolant
line fi ttings.
(b) Damaged compressor head
gasket.
(c) Porous compressor head casting.
Inspect for loose or over-torqued fi ttings.
Reseal and tighten loose fi ttings and plugs
as necessary. If overtorqued fi ttings and
plugs have cracked ports in the head,
replace the compressor.
An air leak at the head gasket may indicate
a downstream restriction such as a freeze-
up or carbon blockage and/or could indicate
a defective or missing safety valve. Find
blockage (go to 9.0(f) for details) and then
replace the compressor. Do not re-use the
safety valve without testing. See Symptom
12.0(a).
If casting porosity is detected, replace the
compressor.
18.0 Noisy
compressor
(Multi-cylinder
compressors only) (a) Damaged compressor. Replace the compressor.
Testing for leaks with
soap solution.
16.0 Compressor
leaks air (a) Compressor leaks air at connections
or ports.
(b) Compressor unloader mechanism
malfunction.
(c) Damaged compressor head
gasket(s).
Check for leaking, damaged or defective
compressor fi ttings, gaskets, etc. Repair
or replace as necessary.
Go to Test 6 on page A-15.
An air leak at the head gasket(s) may
indicate a downstream restriction such as a
freeze-up or carbon blockage and/or could
indicate a defective or missing safety valve.
Find blockage (go to 9.0(f) for details) and
then replace the compressor. Do not re-
use the safety valve without testing. See
Symptom 12.0(a).
Other Miscellaneous Areas to Consider
(b) is not applicable for the
compressor featured in this SD
sheet —- information is shown
for reference only.

Head
gasket
locations
