Troubleshooting
Section
5-3LX 31/41 Work Platform
PROBLEM PROBABLE CAUSE REMEDY
Unit will not 6. Hydraulic Pump Check pump pressure and
drive full speed worn. delivery. Replace if not
(cont'd) serviceable.
7. Bi-Directional Check relief valve and replace
Relief Valves. if inoperable.
8. Torque Selector Test / Replace switch.
Switch.
9. Platform Down Check for contact closure when
Relay. energized. If contacts do not
close, replace the relay.
Unit will not 1. Proportional Check Controller Low Speed
drive (Platform Controller Adjustment. Replace if not
elevated) adjustable.
No drive in one 1. Faulty Drive Test FWD contacts for continuity
direction, Relay. replace relay if required.
other direction 2. Faulty Drive Coil. Test Forward Coil if proper
okay. voltage is present and coil is
not magnetized, replace.
3. Faulty Drive Valve.
Trade FWD and REV valves, if symptoms
change, replace affected valve.
4. Counterballance Trade Counterbalance Valves.
Valves. If symptoms change, replace
affected valve.
Platform drifts 1. Emergency Ensure that the Emergency
down. Lowering/Down Lowering Valve is completely
Valve partly open or closed. If the platform still drifts
faulty. down, replace the valve.
2. Faulty valve Check and replace O-rings on
O-rings. Emergency Lowering/Down
Valve and piston.
3. Lift Cylinder. Open Weep Line, check for
bypass flow.
Platform will 1. Blown fuse. Locate electrical short and then
not lower. replace fuse.
2. Down Valve Test coil and replace if
Solenoid Coil. inoperable.
3. Control Cable. Check cable and replace if
damaged.
4. Lift/Drive Relay. Check down contacts for continuity,
replace relay if necessary.
Brake does 1. Brake Release Valve Open valve.
not release. closed.
2. Brake faulty. Check for oil leakage, replace
brake seals if necessary.
Brake will not 1. Brake Release Valve Open valve.
engage closed.
Table 5-1: Troubleshooting Guide (cont'd.)
5.1
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