Skyjack SJ61T Service Manual

Telescopic Boom Series
Models SJ61T & SJ66T
194312
December 2007 Page 139
Section 4 - Troubleshooting Information Service and Maintenance
7. Defective valve driver channel input for direction sense enable.
- See section 5 for OCM pin voltage reference.
4.1-54 Steer Direction Sensing Inoperative
1. No output on valve driver pin #4 to wire #17A.
- Check pin #4 for 12 volts. If no voltage present with foot on footswitch check section 5 for
OCM pin voltage reference.
2. Loose or broken wire #17A from valve driver pin #4 to relays 17ACR1 and 17ACR2.
- Check continuity. Replace if defective.
3. Loose or broken wire #02 from platform terminal block to relays 17ACR1 and 17ACR2.
- Check continuity. Replace if defective.
4. Defective relays 17ACR1 and 17ACR2.
- Check relay. Replace if defective.
NOTE
If only one relay is bad and one is OK, you will have steer in one di-
rection only.
4.2 Hydraulic System
4.2-1 All Controls Inoperative
1. Broken or defective drive pump shaft or coupling.
- Check pump shaft and coupling. Replace if defective.
2. Hydraulic oil level low.
- Check oil level. Fill to proper level.
4.2-2 All Boom Functions Inoperative
1. Open or defective dump/ enable valve 2H-21A.
- Clean valve. Check O-rings on valve. Check operation of valve. Repair or replace valve as
required.
2. Stuck or defective relief valve RV1.
- Set valve to specications. Check O-rings and clean valve. Repair or replace valve as required.
3. System pump P2 out of adjustment or is defective.
- Refer to section 5 for pump set up procedure. Replace if defective.
4. Defective load sense adjusting valve 3H-V2.
- Check valve. Replace if defective.
5. Defective pressure compensator valve 3H-V1.
- Check valve. Replace if defective.
6. Plugged or defective high pressure lter F1.
- Check lter. Replace if plugged or defective.
4.2-3 No Main Boom Up
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 up valve 4H-14.
- 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.

Skyjack SJ61T Specifications

General

Brand	Skyjack
Model	SJ61T
Category	Lifting Systems
Language	English