CRANE CONTROLS WILL NOT RESPOND.

TM 5-2420-224-20-1

Table 3-5. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

BACKHOE (SEE) (CONT)

b. Disconnect tube (1) at B port of boom section (2) and remove fitting

(3) and restrictor (4) from B port.

If restrictor was incorrectly installed or is missing, install

restrictor with large end toward boom section.

If restrictor is not missing, notify direct support maintenance.

CRANE (HMMH)

131. CRANE CONTROLS WILL NOT RESPOND.

Step 1.

Check for low oil level in rear hydraulic tank.

If oil level is low, add oil (TM 5-2420-224-10).

If oil level is not low, go to step 2.

Step 2.

Check for loose and damaged hydraulic lines.

If hydraulic lines are loose or damaged, tighten loose

connections or replace hydraulic lines (pages 4-632, 4-634,

4-636, 4-638, 4-640, 4-642, 4-644, 4-646, 4-648).

If hydraulic lines are not loose or damaged, notify direct support

maintenance.

132. CRANE OPERATION SLOWS DOWN.

Step 1.

Check for low oil level in rear hydraulic tank.

If oil level is low, add oil (TM 5-2420-224-10).

If oil level is not low, go to step 2.

Step 2.

Check engine rpm on tachometer. Engine speed should be 1100 rpm.

If engine speed is not 1100 rpm, adjust air cylinder (page 4-77).

If engine speed is 1100 rpm, go to step 3.

Step 3.

Check condition of rear hydraulic tank filters.

If rear hydraulic tank filters are unserviceable, change rear

hydraulic tank filters (page 4-720).

If rear hydraulic tank filters are serviceable, notify direct support

maintenance.

Change 2

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