Skyjack SJKB-40-D - Hydraulic System

SECTION 4, Page 28 SJKB-40-D, SJKB-40-D/FJUN. 1999
TROUBLESHOOTING
HYDRAULIC SYSTEM
TROUBLE PROBABLE CAUSE REMEDY
NOTE: ALL TESTS SHOULD BE PERFORMED WITH BOOM OVER NON-STEERING AXLE
ALL FUNCTIONS INOP-
ERATIVE
1. Broken or defective Pump
Coupling.
1. Check Coupling. Replace if
defective.
ALL BOOM FUNCTIONS
INOPERATIVE
1. Defective system relief valve.
2. Stuck or defective dump valve 2H-
21A..
3. Stuck or defective proportional
valve 2H-12..
4. Defective system pump P2.
1. Check Shuttle Valve. Replace if
defective.
2. Check Shuttle Valve. Replace if
defective.
3. Check Shuttle Valve. Replace if
defective.
4. Check Pump. Replace if
defective.
NO TURRET LEFT 1. Stuck or defective turret rotate
left valve 4H-32A.
2. Stuck or defective relief valve
RV2.
3. Stuck or defective relief valve
RV3.
4. Defective turret rotation motor
M2.
5. Stuck or defective counter
balance valve CB10.
6. Turret rotation speed control
valve FC1 out of adjustment.
1. Clean Valve. Replace if defective.
2. Clean Valve. Replace if defective.
3. Clean Valve. Replace if defective.
4. Check Motor. Replace if
defective.
5. Clean Valve. Replace if defective.
6. Refer to section 2, page 5.
NO TURRET RIGHT
1. Stuck or defective turret rotate
right valve 4H-33A.
2. Stuck or defective relief valve
RV2.
3. Stuck or defective relief valve
RV3.
4. Defective turret rotation motor
M2.
5. Stuck or defective counter
balance valve CB11.
6. Turret rotation speed control valve
FC1 out of adjustment.
1. Clean Valve. Replace if defective.
2. Clean Valve. Replace if defective.
3. Clean Valve. Replace if defective.
4. Check Motor. Replace if
defective.
5. Clean Valve. Replace if defective.
6. Refer to section 2, page 5.
TURRET ROTATION
BRAKE WILL NOT RE-
LEASE
1. Stuck or defective shuttle valve
SV-3.
2. Stuck or defective brake pack BP-
1.
1. Clean Valve. Replace if defective.
2. Rebuild Cylinder. Replace if
defective.
NO STEER RIGHT
1. Stuck or defective steer right
valve 4H-23A.
2. Blown seals in rotary manifold.
3. Steer cylinder bypassing
internally.
1. Clean Valve. Replace if defective.
2. Rebuild Rotary Manifold. Replace
if defective.
3. Rebuild Cylinder. Replace if
damaged.