User Manual

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

Head
gasket
locations

(b) is not applicable for the
compressor featured in this SD
sheet —- information is shown
for reference only.