MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
Step 1. The first thing that SGT Moore does is attempt to engage the
power takeoff according to the procedures contained on pages 2-128
thru 2-131 of TM 9-2320-272-10.
Since the power takeoff engaged
properly, SSG Moore will proceed to step 2.
Step 2. In this step, SSG Moore checks all the hydraulic lines for
leaks or breaks.
Since there were no leaks or breaks in the
hydraulic lines, SSG Moore will proceed to step 3.
For this step, SSG Moore inspects the control valve for
evidence of leaks and damage. The control valve is not leaking and
does not appear to be damaged in any way, so SSG Moore will proceed
to step 4.
In this step, SSG Moore checks the control valve shaft
movement in and out.
Since the shaft moves in and out, SSG Moore
will proceed to step 5.
In this step, SSG Moore inspects the pump housing for
evidence of leaks and overheating with the power takeoff engaged. In
this instance, when the power takeoff is engaged, a large quantity of
oil drains from the pump housing, and the pump housing is extremely
warm to the touch. SSG Moore disengages the power takeoff and shuts
down the engine. He now notifies his supervisor and IDS maintenance
that the pump housing is defective and needs to be replaced.
of the M939 FOV.
In the next paragraphs the troubleshooting
procedures for malfunctions occurring in the electrical system will
Electrical Systems Troubleshooting
In the following paragraphs we will again follow a fictitious
individual as they troubleshoot malfunctions within the electrical
subsystems of the M939 FOV.
The troubleshooting test results they
receive are not the only ones possible.
Consult TM 9-2320-272-20-1
when actually performing the troubleshooting procedures.
Battery System Troubleshooting.
In the following paragraphs we
will follow SSG Blackwood as she troubleshoots the battery
system for the malfunction ENGINE WILL NOT CRANK, SOME ELECTRICAL