MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
Step 1. In the first step of the troubleshooting procedure SGT Best
inspects
the
power
takeoff
universal
joint
for
insufficient
lubrication.
Since the universal joint has the proper amount of
lubrication, he proceeds to step 2.
Step 2.
In this step, SGT Best inspects the propeller shaft for
bends.
Finding the hydraulic pump propeller shaft bent, SGT Best
replaces it following the procedures contained in paragraph 10-30, TM
9-2320-272-20-2.
After the propeller shaft has been replaced, SGT Best repeats the
test procedures to ensure that the malfunction has been corrected and
that no additional malfunctions exist.
h.
Dump Body System Troubleshooting.
In the following paragraphs
we will follow SSG Moore as he troubleshoots the dump body system on
an M929 for the malfunction DUMP BODY WILL NOT RAISE and reaches the
conclusion that the pump housing is leaking with the power takeoff
engaged.
The first thing that SSG Moore does is read DA Form 2404 and talk
with the operator.
Once this has been done he reads through the
troubleshooting procedures to determine what tools will be needed.
For this particular malfunction he will only need a mechanic's
general toolbox. After he has gathered the necessary tools together,
he will configure the vehicle according to the items listed in
paragraphs 3a(1) thru 3a(5) on page 34 of this task. Now SSG Moore
is ready to begin the troubleshooting procedure.
WARNING
When the dump body is in the raised position, oil
in the filter system is under pressure.
Any
movements of the control valve, or leakage at the
hydraulic cylinder line or hose connection, will
cause the dump body to drop to the subframe.
Never work under the dump body unless safety
braces have been properly positioned.
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