Air Dryer; Doesn't Purge (14.0); Safety Valve Releases Air (12.0); Constantly Cycles (15.0) - BENDIX TU-FLO 501 AIR COMPRESSOR Manual

Symptom:

12.0 Air dryer

safety valve
releases air.
Air dryer
safety valve
Technician removes
governor.
13.0 Reservoir
safety valve
releases air
14.0 Air dryer
doesn't purge.
(Never hear
exhaust from air
dryer.)
15.0 Compressor
constantly cycles
(compressor
remains unloaded
for a very short
time.)
24
What it may indicate:
(a) Restriction between air dryer and
reservoir.
(b) Air dryer safety valve malfunction.
(c) Air dryer maintenance not
performed.
(d) Air dryer malfunction.
(e) Improper governor control line
installation to the reservoir.
(f) Governor malfunction.
(a) Reservoir safety valve malfunction.
(b) Governor malfunction.
(c) Compressor unloader mechanism
malfunction.
(a) Air dryer malfunction.
(b) Governor malfunction.
(c) Air brake system leakage.
(d) Improper governor control line
installation to the reservoir.
(a) Air brake charging system
maintenance not performed.
(b) Compressor unloader mechanism
malfunction.
(c) Air dryer purge valve or delivery
check valve malfunction.
(d) Air brake system leakage.
What you should do:
ð Inspect delivery lines to reservoir for
restrictions and repair as needed.
ð Verify relief pressure is at vehicle or
component manufacturer specifications.
Replace if defective.
ð See Maintenance Schedule and Usage
Guidelines (Table A, column 3, on page
15).
ð Verify operation of air dryer. Follow vehicle
O.E. maintenance recommendations and
component Service Data information.
ð Go to Test 5 on page 27.
ð Go to Test 4 on page 27.
ð Verify relief pressure is at vehicle or
component manufacturer's specifications
(typically 150 psi). Replace if defective.
ð Go to Test 4 on page 27.
ð Go to Test 6 on page 27.
ð Verify operation of air dryer. Follow vehicle
O.E. maintenance recommendations.
ð Go to Test 4 on page 27.
ð Go to Test 2 on page 26.
ð Go to Test 5 on page 27.
ð Available reservoir capacity may be
reduced by build up of water etc. Drain
and perform routine maintenance per
Table A, columns 3 & 4, on page 15.
ð Go to Test 6 on page 27.
ð Verify operation of air dryer. Follow vehicle
O.E. maintenance recommendations and
component Service Data information.
ð Go to Test 2 on page 26.