TM 9-2320-272-24-2
Table 4-1. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
59. DUMP HOIST IS INOPERATlVE OR OPERATES SLOWLY
WARNING
When dump body is in a raised position, oil in hydraulic system
l
is under pressure. Any movement of control valve or leakage at
the hydraulic cylinder lines or connections will cause dump body
to drop to the subframe. Never work under dump body unless
safety braces are properly positioned. Failure to do so may
cause injury or death.
l Do not loosen or take off any lines or hoses while the engine is
running with the PTO engaged. Failure to do so may cause
injury.
Before
performing the troubleshooting procedure, complete the following preliminary inspections:
Check hydraulic reservoir oil level. If low, fill to top (LO 9-2320-272-12).
1.
Check hydraulic oil for contamination (TB 43-0211).
2.
Replace hydraulic oil filter (para. 3-336).
3.
Check pump, cylinders, control valve, lines, and hoses for deterioration and leaks. Tighten
4.
any loose connections. Replace any component where either class II or class III leaks are
found (chapter 4, section XIV).
Check that PTO control lever moves freely and fully engages and disengages the PTO. If
5.
PTO will not engage, replace PTO (para. 4-211).
Check that dump control lever moves freely. Inspect control cable adjustment at valve. If
6.
valve spool will not fully shift, replace control valve (para. 4-151).
Ensure latch releases dump hoist when dump body is raised. If latch fails to release dump
7.
hoist, lubricate latch (LO 9-2320-272-12). If latch still fails to release, replace latch.
Ensure latch secures dump hoist to subframe when dump body is resting on subframe.
8.
Lubricate latch assembly (LO 9-2320-272-12). If latch fails to secure dump body, replace
latch.
CAUTION
When disconnecting hydraulic oil lines and hoses, plug all
openings to prevent dirt from entering and causing internal parts
damage.
NOTE
Have drainage container ready to catch excess oil.
Step 1. Remove hydraulic pump-to-control valve line and check for blockage (para. 4-147).
a. If blockage is present, replace and retest dump operation.
b. If blockage or obstruction is not present, proceed to step 2.
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