Skyjack SJ12 Service Manual

85
SJ12, SJ16
213558ADA
Hydraulic System Troubleshooting Section 4 – Troubleshooting Information
4.3-6 Platform Will Not Lower
1. Defective Holding/Emergency Lowering valve
2H-13.
Check valve. Replace if defective.
2. Lowering orifice O1 plugged or contaminated. Clear debris from Orifice. Replace if defective.
4.3-7 Pothole Bars Will Not Retract
1. Defective or sticking Pothole valve 2H-21. Check valve. Replace if defective.
2. Defective or binding Pothole Cylinder. Check for mechanical binding. Rebuild cylinder
seals. Replace if defective.
4.3-8 Platform Drives Slow
1. Drive motor M1 or M2 defective. Check motors. Replace if defective.
4.3-9 Platform Will Not Drive in Forward
1. Forward drive valve 4H-16A defective or is
sticking.
Clean Valve. Replace if defective.
2. Counterbalance valve CB1 defective or is
plugged.
Clean Valve. Replace if defective.
4.3-10 Platform Will Not Drive in Reverse
1. Reverse drive valve 4H-15A defective or is
sticking.
Clean Valve. Replace if defective.
2. Counterbalance valve CB1 defective or is
plugged.
Clean Valve. Replace if defective
4.3-11 Brake(s) Will Not Release
1. Brake valve 2H-17 defective or is sticking. Clean valve. Replace if defective.
2. Brake Override Valve V1 is defective. Check valve. Replace if defective.
3. Defective Brakes BR1 and/or BR2. Inspect wheel motor assembly. Check if hydraulic
pressure is available at brake hubs.Rebuild/repair
brake hubs if required. Replace if defective.

Skyjack SJ12 Specifications

General

Gradeability	25%
Drive Motor	24V DC
Machine Width	32 in (0.81 m)
Stowed Height	6.5 ft
Overall Width	32 in (0.81 m)
Stowed Height (Rails Folded)	6.5 ft
Drive Speed (Elevated)	0.5 mph (0.8 km/h)
Power Source	Electric