TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
70.
PARKING BRAKE DOES NOT RELEASE - CONTINUED.
NOTE
Check AIR PRESSURE gage for air pressure between 90 and 130 psi. If specified air pressure is
not present, start engine. Raise air pressure between 90 and 130 psi then shut down engine (TM
5-3805-254-10).
Step 7.
Check front rear quick release valve (1) for output air pressure as follows: have assistant pull out
PARKING BRAKE control knob (2). Using 3/4-inch open-end wrench, loosen output hose fitting (3)
six turns. Have assistant push in PARKING BRAKE control knob (2). Listen for hissing noise.
a. If hissing noise is not heard, defective front rear quick release valve (1) must be
replaced. Notify Direct Support Maintenance.
b. If hissing noise is heard, go to step 8.
Step 8.
Check rear rear quick release valve (4) for output air pressure as follows: have assistant pull out
PARKING BRAKE control knob (2). Using 3/4-inch open-end wrench, loosen output hose fitting (5)
six turns. Have assistant push in PARKING BRAKE control knob (2). Listen for hissing noise.
a. If hissing noise is not heard, defective rear rear quick release valve (4) must be
replaced. Notify Direct Support Maintenance.
b. If hissing noise is heard, notify Direct Support Maintenance.
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