TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
69.
PARKING BRAKE DOES NOT HOLD - CONTINUED.
NOTE
Check AIR PRESSURE gage for air pressure between 90 and 130 psi. If specified air pressure is
not present, start engine and check that air pressure in air system is between 90 and 130 psi (TM
5-3805-254-10). Shut down engine (TM 5-3805-254-10).
Step 4.
Check rear relay valve (1) for air pressure as follows: have assistant push in PARKING BRAKE
control knob (2). Check for exahust of air pressure from exhaust vent (3) on bottom of rear relay
valve (1).
a. If air pressure is not vented from exhaust vent (3), rear relay valve (1) must be
replaced. Notify Direct Support Maintenance.
b. If air pressure is vented from exhaust vent (3), have assistant pull out PARKING
BRAKE control knob (2). Go to step 5.
Step 5.
Check front rear quick release valve (4) for air pressure as follows: have assistant push in
PARKING BRAKE control knob (2). Check for exhaust of air > pressure from exhaust vent (5) on
bottom of front rear quick release valve (4).
a. If air pressure is not vented from exhaust vent (5), front reqr quick release valve (4)
must be replaced. Notify Direct Support Maintenance.
b. If air pressure is vented from exhaust vent (5), have assistant pull out PARKING
BRAKE control knob (2). Go to step 6.
Step 6.
Check rear rear quick release valve (6) for air pressure as follows: have assistant push in PARKING
BRAKE control knob (2). Check for exhaust of air pressure from exhaust vent (7) on bottom of rear
rear quick release valve (6).
a. If air pressure is not vented from exhaust vent (7), rear rear quick release valve (6)
must be replaced. Notify Direct Support Maintenance.
b. If air pressure is vented from exhaust vent (7), have assistant pull out PARKING
BRAKE control knob (2). Go to step 7.
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