12 No Brake Function - Skyjack SJ85 AJ Service Manual

Section 4 – Troubleshooting Information

4.3-12 No Brake Function

Brake will not Release:
1. Stuck or defective shuttle valve SV2.
2. Defective or misadjusted pressure reducing valve
PR1.
3. Stuck or defective brake valve 3H-26.
4. Stuck or defective shuttle valve SV6.
5. Defective or misadjusted relief valve RV5.
6. Stuck or defective brake release override valve
V1.
7. Bypassing or defective brake hand pump V3.
8. Bypassing or defective brake piston on front or
rear axle C9 or C10.
Brake will not Engage:
1. Brake return spring or defective cylinder.
2. Stuck or defective brake valve 3H-26.
3. Brake in axle out of adjustment.
229044ADA
138
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
Set valve to specifications. Check O-rings and
clean valve. Repair or replace valve as required.
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
Set valve to specifications. Check O-rings and
clean valve. Repair or replace valve as required.
Clean valve. Check O-rings on valve. Repair or
replace valve as required.
Clean valve. Check O-rings on valve. Repair or
replace valve as required.
Check seals on pistons (axle oil level overfull).
Replace as necessary.
Check cylinder. Repair or replace as necessary.
Clean valve. Check O-rings on valve. Check
operation of valve. Repair or replace valve as
required.
See section 5 for brake adjustment procedure.
Hydraulic System
SJ85 AJ