14 No Drive; 15 Differential Lock Will Not Engage; 16 No High Speed Drive - Skyjack SJ82 T Service Manual

Hydraulic System

4.3-14 No Drive

Forward or Reverse
1. Brake not releasing.
2. Defective or misadjusted charge pump relief
valve RV8.
3. Worn charge pump P1A.
4. Defective pump displacement control 4H-15 and
4H-16.
5. Open bypass valve V6.
6. Worn or defective drive pump P1.
7. Worn or defective drive motor M1.
Forward Drive
1. Defective pump displacement control 4H-16.
2. Defective or misadjusted drive relief valve RV6.
Reverse Drive
1. Defective pump displacement control 4H-15.
2. Defective or misadjusted drive relief valve RV7.

4.3-15 Differential Lock will not Engage

1. Stuck or defective differential lock valve 3H-165.
2. Bypassing or defective differential lock cylinder
C10.

4.3-16 No High Speed Drive

1. Stuck or defective 2 speed valve 3H-45.
2. Defective shift spool in drive motor M1.
SJ82 T, SJ86 T
Section 4 – Troubleshooting Information
See "brake will not release" in this section.
Set valve to specifications. Check O-rings and
clean valve. Repair or replace valve as required.
Check pump. Replace if defective.
Check control. Replace if defective.
Close bypass valve.
Check pump. Replace if defective.
Check motor. Replace if defective.
Check control. Replace if defective.
See section 5 for drive pump set up procedures.
Check control. Replace if defective.
See section 5 for drive pump set up procedures.
Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
Check seals on cylinder. Replace as necessary.
Replace cylinder if defective
Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
Check motor. Repair or replace if necessary.
229040ABA
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