TM-9-2320-272-23-2
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 2 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-2 - Page 329 of 1417
NG90: GOVERNOR/POWER TEST FAULT ISOLATION - Continued
STEP
6.
Compare test results.
Ensure compression unbalanced test readings are within limits.
Table
4.
Compression Unbalance Test Limits.
VEHICLE
COMPRESSION UNBALANCE TEST LIMITS
M939/A1
8-10%
M939A2
0-15%
CONDITION/INDICATION
Is compression unbalance within the limits specified?
DECISION
YES - Go to NG130: Engine Tightness Test (WP
0205).
NO - Repeat G08: Compression Unbalance Test (WP
0195). If still NO, notify supervisor. After completing repair,
rerun GO-Chain tests to verify the problem is fixed and no other problems exist.
STEP
7.
Check if VTM displays GO.
CONDITION/INDICATION
Does VTM display GO?
DECISION
YES - Repeat Step (5).
NO - Go to Step (8).
STEP
8.
Check if VTM displays FAIL.
CONDITION/INDICATION
Does VTM display FAIL?
DECISION
YES - Repeat G08: Compression Unbalance Test (WP
0195).
NO - VTM displays E013. This may indicate discharged batteries or low cranking speed. Also, operator may
have stopped cranking during test. Check and repeat test.
END OF WORK PACKAGE
TM 9-2320-272-23-2
0204
0204-6
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