JLG 1500SJ Service Manual - Manual (Page 437)

SECTION 5 - HYDRAULICS
3121262 – JLG Lift – 5-85
If difficulties are encountered in obtaining neutral position
of the HD or EP control modules, check that the ends of
the control spring are correctly located in the grooves
near the end of the feedback lever arms.
High Pressure Relief Valve Adjustments
1. Remove relief valve cover from pump (ref. item 1).
2. Loosen jam screw (ref. item 2).
3. Holding spring loading nut (ref. item 4) rotate valve
spindle (ref. item 3). For high range relief valve, one
turn equals approximately 630 psi (44 bar). For low
range relief valve, one turn equals approximately
377 psi (26 bar).
4. After adjustment is completed torque jam screw (ref.
item 4) to 5 ft.lb. (7 Nm).
5. Install relief valve assembly into pump, reinstall
cover (ref. item 1) to proper torque.
Removal and inspection of charge pump
Before removing cap screws, mark the position of the
charge pump housing and separator plate in relation to
the port block.
Loosen screws with metric allen wrench.
Remove charge pump housing and inspect for wear or
damage to gear set and 0-ring seals. Grease 0-rings prior
Table 5-6. Torque Specs for Relief Valves into Port Block
Pump Size Wrench Size Torque
28 32 mm 66 ft.lb. (90 Nm)
Pump Size Allen Wrench
28 8 mm