TM 5-5420-209-12
Table 4-4. Unit Troubleshooting. - Continued
Malfunction
Test or Inspection
Corrective Action
7.
LOCKING CYLINDER INOPERATIVE - Continued
Step 3.
Test cylinder for internal damage. Disconnect upper (rod end) hose from cylinder port,
momentarily position control valve to PIN-OUT, and check for oil flow from open port.
a.
If oil discharges from open port (cylinder operates), stop, connect upper hose and refer to
Step 4.
b.
If no oil flows from open port, reconnect upper hose and disconnect lower hose.
Momentarily position control valve to PIN-OUT and check for oil flow from lower port.
c.
If there is no oil flow from lower part, stop, connect hose and refer to Step 4.
d.
If oil flow is present from lower port, cylinder is faulty. Replace defective cylinder.
Step 4.
Test for faulty dual overcenter valve. Disconnect input line (Port V1) to dual overcenter valve,
momentarily position control valve to PIN, and check for oil flow.
a.
If there is no oil from line, refer to Step 5.
b.
If there is oil flow, reconnect input line, disconnect return line (Port Cl), momentarily
position control valve to PIN, and check for oil flow.
c.
If there is no oil flow, replace dual overcenter valve.
Step 5.
Test for faulty control valve. Disengage PTO, disconnect input line (fitter) to control valves,
engage PTO momentarily, and check for oil flow.
a.
If oil flow is not present, refer to malfunctions 9 and 10.
b.
If oil flow is present, reconnect input line and disconnect output line of valve section.
Momentarily position control valve to PIN and check for oil flow.
c.
If no oil flow is present, reconnect output line and disconnect return line to reservoir.
Momentarily position control valve to PIN and check for oil flow.
d.
If no oil flow is present, replace control valve.
4-31
