BENDIX BA-922 COMPRESSOR Manual page 19

Symptom:
6.0 Excessive oil
consumption in
engine.
7.0 Oil present
at air dryer
cartridge during
maintenance.
8.0 Oil in ping tank
or compressor dis-
charge aftercooler.
9.0 Air brake
charging system
seems slow to
build pressure.
What it may indicate:
A problem with engine or other engine
accessory.
The engine
service
manual
has more
information.
Air brake charging system is functioning
normally.
Oil shown
leaking
from an
air dryer
cartridge.
Air brake charging system is functioning
normally.
(a) Air brake charging system
functioning normally.
(b) Air brake system leakage.
(c) Compressor may be undersized for
the application.
(d) Compressor unloader mechanism
malfunction.
(e) Damaged compressor head
gasket.
What you should do:
 See engine service manual.
 Air dryers remove water and oil from
the air brake charging system. A small
amount of oil is normal. Check that regular
maintenance is being performed and that
the amount of oil in the air tanks (reservoirs)
is within the acceptable range shown by
the BASIC Test (see also column 5 of
Table A on page 13). Replace the air dryer
cartridge as needed and return the vehicle
to service.
 F o l l o w v e h i c l e O . E . m a i n t e n a n c e
recommendation for these components.
 Using dash gauges, verify that the
compressor builds air system pressure
from 85-100 psi in 40 seconds or less with
engine at full governed rpm. Return the
vehicle to service.
 Go to Test 2 on page 24.
 See Table A, column 1, on page 13 for some
typical compressor applications. If the
compressor is "too small" for the vehicle's
role, for example, where a vehicle's use has
changed, then upgrade the compressor.
Note: The costs incurred (e.g. installing
a larger capacity compressor, etc.) are
not covered under original compressor
warranty.
 Go to Test 6 on page 25.
 An air leak at the head gasket may indi-
cate 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).
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