SECTION 4, Page 10
SJIII Series - The Conventionals 129919
Troubleshooting Information - Hydraulic System
Probable Cause Remedy
4.2-1. All Functions Inoperative
1. Proportional Valve (2H-59B) defective or is sticking.
2. Compensator Valve (CMP1) defective or is sticking.
3. Pump (P1) defective.
1. Check valve. Replace if defective.
2. Check valve. Replace if defective.
3. Check pump. Replace if defective.
4.2-2. Platform Drifts Down
1. Defective Lift Cylinder Seals.
2. Combination of:
Defective Holding Valves (2H-13-1) and (2H-13-2) and
either defective Lowering Valve (2H-13) or Relief Valve
(R2) or Manual Lowering Valve (V1).
1. Rebuild cylinder. Replace if damaged.
2. Check valves. Replace if defective.
4.2-3. Platform Lifts Slowly
1. Open or leaking Manual Lowering Valve (V1).
2. Lift Relief Valve (R2) defective.
3. Open Manual Override on Holding Valve (2H-13-1)
or (2H-13-2).
1. Close valve. Replace if defective.
2. Check valve. Replace if defective.
3. Depress and turn manual override clockwise to
close. Replace if defective.
4.2-4. Platform Does Not Lift
1. Open Manual Lowering Valve (V1).
2. Hydraulic oil level too low.
3. Platform weight excessive.
4. Up Valve (3H-14) defective or is sticking.
1. Close valve. Replace if defective.
2. Fully lower the platform. Fill hydraulic tank until fluid
is at or slightly above the top mark on the sight glass.
3. Reduce platform load to maximum capacity.
4. Check valve. Replace if defective.
4.2-5. Platform Will Not Lower (NOTE: Down Function Is NOT Proportionally Controlled)
1. Lowering Valve (2H-13) defective or is sticking.
2. Defective Holding Valve (2H-13-1) or (2H-13-2).
1. Clean valve. Replace if defective.
2. Check valve. Replace if defective.
4.2-6. Platform Drives Slow
1. Free-Wheeling Valve (V2) open or defective.
2. Flow Divider/Combiner (FD1) defective or is
plugged.
3. Drive Motor (M1) or (M2) defective.
4. Cushion Cylinder (C-1) defective.
1. Close valve. Replace if defective.
2. Check valve. Replace if defective.
3. Check motors. Replace if defective.
4. Check cylinder. Replace if defective.
4.2-7. Platform Will Not Drive In Forward Or Reverse
1. Open Free-Wheeling Valve (V2).
2. Forward Drive Valve (4H-16) or Reverse Drive Valve
(4H-15) defective or is sticking.
3. Flow/Divider/Combiner Valve (FD1) defective or is
plugged.
4. Counterbalance Valve (CB1) defective or is plugged.
1. Close Valve. Replace if defective.
2. Clean Valve. Replace if defective.
3. Clean Valve. Replace if defective.
4. Clean Valve. Replace if defective.
4.2-8. Brake(s) Will Not Release
1. Brake Valve (3H-17A) defective or is sticking.
2. Brake Orifice(s) (05) plugged.
3. Brake Cylinder(s) (C4) defective.
(Machines with Integral Brakes)
4. Plugged or defective brake orifice (07).
5. Damaged integral brake in wheel motor.
1. Clean valve. Replace if defective.
2. Remove orifice(s). Clean and reinstall.
3. Rebuild cylinder(s). Replace if damaged.
4. Clear obstruction. Replace if defective.
5. Inspect wheel motor assembly. Repair and replace
as necessary.
AF
To Next Page
Loading...
