Skyjack SJ12 E - 7.5 Environment

69
SJ12 E, SJ16 E, SJ20 E
241914ACA
Hydraulic System Section 4 – Troubleshooting Information
4.3 Hydraulic System
4.3-1 All Hydraulic Controls Inoperative (No Lift or Steer functions)
1. Pump motor not engaged
Refer to Electrical troubleshooting. Replace pump
motor if defective.
2. Pump motor coupler defective Check coupler. Replace if defective
3. Defective pump P1 Check pump output. Replace if defective.
4. System relief valve RV1 set too low or stuck
open.
Check and adjust valve setting. Replace if
defective.
4.3-3 No Lower Function
1. Stuck or defective lift valve 3H-14
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
2. Stuck or defective lower valve 2H-13
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
3. Blocked lower orice OR1 Check orice. Clean or replace as required
4. Defective lift Cylinder assembly Check cylinders. Repair or replace as required.
4.3-4 No Steer Left and/or Right
1. Stuck or defective steer valve 4H-23/4h-24
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
2. Steer crossover relief valve RV2 set too low or
stuck open.
Check and adjust valve setting. Replace if
defective.
3. Steer cylinder C5 bypassing, or mechanically
binding
Check cylinder and all steer linkage. Repair or
replace defective componants as required.
4. Stuck or defective RV1 Adjust or replace if defective.
4.3-2 No Lift Function
1. Check valve CV1 stuck closed
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
2. Stuck or defective lift valve 3H-14
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
3. Defective lift Cylinder assembly Check cylinders. Repair or replace as required.
4. Stuck or defective RV1 Adjust or replace if defective.