Table 1. Unit Preventive Maintenance Checks and Services (PMCS)
for the M915A3 Tractor Truck - Continued.
NOT FULLY MISSION
e. Start vehicle moving downhill. Engage
engine Jake brake and check operation in
all switch positions (2, 4, and 6 cylinders
braking power). Ensure that vehicle
speed drops in each position, with maxi-
mum braking power with all 6 cylinders
engaged in braking.
Cautiously feel each wheel hub and brakedrum. Wheel hubs and brake-
drums may be hot. Failure to follow this warning may result in serious
f. Immediately after road test, carefully
check and compare each wheel hub and
brakedrum for overheating, which could
indicate a dragging brake. A cool wheel
hub and brakedrum could mean improp-
erly adjusted, defective or inoperative
Check operation of interaxle lockout.
Check vehicle response to steering wheel
action. Vehicle should respond quickly.
With vehicle on straight level ground,
lightly hold steering wheel to check for pull
or wander. With vehicle in motion, free play
should be no more than 2 ½ in (6.4 cm) in
Observe how vehicle responds to road
shocks. Shifts, knocks or constant bouncing
indicate possible malfunctions.