TM-9-2320-272-23-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-1 - Page 1164 of 1313
FRONT WHEEL DRIVE DOES NOT ENGAGE (FRONT WHEEL DRIVE LOCK-IN SWITCH ENGAGED AND
TRANSFER CASE SHIFT LEVER IN HIGH POSITION) - Continued
STEP
8.
IS THERE AIR PRESSURE IN THE AIR LINE BETWEEN THE ACTUATOR VALVE AND THE TRANSFER
CASE?
a.
Verify engine is stopped.
b.
Disconnect delivery air line from transfer case. Refer to point to point schematics.
T0351DAA
ACTUATOR
VALVE
DELIVERY
LINE
SUPPLY
LINE
TRANSDUCER
Figure 8.
Actuator Valve.
c.
Connect pressure gauge to disconnected air line.
d.
Start engine and run at idle.
e.
Place transfer case shift lever into low position.
f.
Monitor air pressure on pressure gauge.
g.
After 5 minutes air pressure should read 90 to 130 psi.
CONDITION/INDICATION
IS THERE AIR PRESSURE IN THE AIR LINE BETWEEN THE ACTUATOR VALVE AND THE TRANSFER
CASE?
DECISION
YES - Notify supervision that transfer case is faulty. Action may not be possible at this level of maintenance.
NO - Go to Step (9).
TM 9-2320-272-23-1
0140
0140-9
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