Skyjack SJ61T, Service Manual

Page: 140 / 232

Page 140 December 2007
Telescopic Boom Series
Models SJ61T & SJ66T
194312
Section 4 - Troubleshooting Information Service and Maintenance
5. Stuck or defective counterbalance valve CB3.
- Clean valve. Check O-rings on valve. Repair or replace valve as required.
6. Defective lift cylinder C1.
- Check seals on cylinder. Replace as necessary. Replace cylinder if defective.
4.2-4 No Main Boom Down
1. Stuck or defective differential sensing valve DSV2.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
2. Stuck or defective lift down valve 4H-13.
- Clean valve. Check operation of valve. Repair or replace valve as required.
3. Stuck or defective shuttle valve SV2.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
4. Stuck or defective check valve CV5.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
5. Stuck or defective counterbalance valve CB3.
- Clean valve. Check O-rings on valve. Repair or replace valve as required.
6. Defective lift cylinder C1.
- Check seals on cylinder. Replace as necessary. Replace cylinder if defective.
4.2-5 No Turret Rotate Left
1. Stuck or defective differential sensing valve DSV1.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
2. Stuck or defective rotate left valve 4H-32.
- Clean valve. Check operation of valve. Repair or replace valve as required.
3. Stuck or defective shuttle valve SV1.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
4. Stuck or defective check valve CV4.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
5. Stuck or defective relief valve RV2.
- Set valve to specifications. Check O-rings and clean valve. Repair or replace valve as required.
6. Stuck or defective shuttle valve SV7.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
7. Stuck or defective counterbalance valve CB2.
- Clean valve. Check O-rings on valve. Repair or replace valve as required.
8. Turret rotate brake BR1 not releasing.
- Inspect brake for worn seals or broken components. Repair and replace as necessary.
9. Worn or defective swing drive motor M2.
- Check motor. Repair or replace if defective.
4.2-6 No Turret Rotate Right
1. 1. Stuck or defective differential sensing valve DSV1.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
2. Stuck or defective rotate right valve 4H-33.
- Clean valve. Check operation of valve. Repair or replace valve as required.
3. Stuck or defective shuttle valve SV1.