BENDIX BA-921 Service Data page 11

BACK / RETOUR
SYMPTOMS
1. Compressor passes
excessive oil as evidenced
by presence of oil at
the exhaust ports of
valving.
COMPRESSOR TROUBLESHOOTING CHART
CAUSE
A. Restricted air intake.
B. Restricted oil return to
engine.
C. Poorly filtered inlet air.
D. Insufficient compressor
cooling (compressor runs
hot).
E. Contaminants not being
regularly drained from
system reservoirs.
REMEDY
A. Check engine air cleaner and replace if
necessary. Check compressor air inlet for kinks,
excessive bends and be certain inlet lines have
minimum specified inside diameter. Recommended
maximum air inlet restriction is 25" of water.
B. Oil return to the engine should not be in any way
restricted. Make certain oil drain passages in the
compressor and mating engine surfaces are
unobstructed and aligned. Correct gaskets must
be used. Special care must be taken when seal
ants are used with, or instead of, gaskets.
C. Check for damaged, defective or dirty air filter on
engine or compressor. Check for leaking, damaged
or defective compressor air intake components
(e.g. induction line, fittings, gaskets, filter bodies,
etc.). The compressor intake should not be
connected to any part of the exhaust gas
recirculation (E.G.R.) system on the engine.
D. For water-cooled portions of the compressor:
1. Check for proper coolant line sizes. Minimum
recommended size is 3/8" I.D. tubing.
2. Check the coolant flow through the compressor.
Minimum allowable flow is 2.5 gallons per
minute at engine governed speed. If low cool
ant flow is detected, inspect the coolant lines
and fittings for accumulated rust scale, kinks
and restrictions.
3. Water temperature should not exceed 200
degrees Fahrenheit.
4. Optimum cooling is achieved when engine
coolant flows, as shown in Figure 8 of this
manual.
E. Check reservoir drain valves to insure that they
are functioning properly. It is recommended that
the vehicle should be equipped with functioning
automatic drain valves, or have all reservoirs
drained to zero (0) psi daily, or optimally to be
equipped with a desiccant-type air dryer prior to
the reservoir system.
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