Skyjack SJ16 - Hydraulic System Troubleshooting

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SJ12, SJ16
Section 4 – Troubleshooting Information Hydraulic System Troubleshooting
4.3 Hydraulic System Troubleshooting
4.3-1 All Functions Inoperative
1. Electric Motor DCM1 not engaged. Refer to electrical troubleshooting.
2. Pump P1 and/or pump coupler defective. Check system pressures and Pump P1
functionality. Replace if defective.
3. System Relief valve R1 stuck open. Clean valve. Replace if defective.
4.3-2 All System Sluggish
1. System relief valve R1 defective or not adjusted
properly.
Adjust valve. Replace if defective.
2. Hydraulic pump P1 worn or strainer
contaminated. .
Check system pressure and flow from Pump P1.
Replace if defective.
4.3-3 Platform Drifts Down
1. Defective Lift cylinder seals at the gland. Replace if damaged.
Note: There are no piston seals, just wear rings.
2. Combination of stuck or defective Holding/
Emergency Lowering valves 2H-13.
Check valve. Replace if defective.
4.3-4 Platform Lifts Slowly
1. Defective or stuck Holding/Emergency Lowering
valve 2H-13
Check valve. Replace if defective.
2. Lift relief valve R3 defective or is not set correctly. Check pressures and adjust if necessary. Replace if
defective.
4.3-5 Platform Does Not Lift
1. Defective Lift valve 4H-14A. Check valve. Replace if defective.
2. Hydraulic oil level too low. Fully lower the platform. Fill hydraulic tank until
fluid is at or slightly above the top mark on the
sight glass.
3. Lift Relief valve R3 is defective or is set
incorrectly.
Check pressures and adjust if necessary. Replace if
defective.
4. Platform weight excessive. Reduce platform load to maximum capacity.