Table 4-4. Unit Troubleshooting. - Continued
Malfunction
Test or Inspection
Corrective Action
3.
BOOM INOPERATIVE - Continued
NOTE
On Model RBT ensure the selector valve is in the REAR HYDRAULICS position.
Step 1.
Check that bridge bay locking pin is retracted.
Position control valve to PIN OUT.
Step 2.
Inspect all hydraulic lines and hoses for evidence of external damage.
Replace tubes or hoses that are dented, ruptured, pinched or crimped.
Step 3.
Test boom cylinders for internal damage.
a.
Disconnect upper hose from one cylinder. Momentarily position control valve to RAISE,
and check for oil from open port.
b.
If oil flows from open port, connect hose and disconnect lower hose and check for oil flow.
c.
If there is no oil flow from the upper port, or there is oil flow from the lower port, the
cylinder is defective.
d.
Replace faulty cylinder.
4.
WINCH DOES NOT OPERATE
WARNING
When disconnecting any hydraulic line, open line slowly and protect face, as hydraulic oil may spray out
due to residual pressure in system.
Step 1.
Inspect hydraulic lines and hoses for external damage and security.
Replace tubes or hoses that are dented, pinched, crimped, or ruptured.
Step 2.
Check oil level of winch.
Service winch assembly as necessary.
4-28
TM 5-5420-209-12
