JLG 340AJ Service Manual - Manual (Page 232)

SECTION 5 - HYDRAULICS
5-74 – JLG Lift – 3121259
Pressure Limiter Valve Replacement
Replace the pressure limiter valve as a complete unit. Do not
attempt to repair individual components. See Pressure limiter
adjustment for adjustment instructions.
REMOVAL, INSPECTION, ASSEMBLY
1. Using a 14 mm wrench, remove the pressure limiter
valve (L100). Discard O-ring.
2. Inspect the sealing surfaces of the pump for nicks or
scratches.
3. Install new O-ring. Lubricate O-ring with petroleum jelly.
4. Replace pressure limiter valve. Torque to 30 Nm [22
lb.ft.].
5. Operate pump at full range of controls to ensure proper
machine operation. Pressure limiter is available as com-
plete unit only. O-ring is available separately.
5.4 GEAR PUMP
Disassembly
Prior to proceeding with disassembly, it may be necessary to
prepare some subassemblies separately.
The details for preparing each subassembly are given in the
following section.
Also, some general recommendations are given below.
CLEANLINESS
Cleanliness is a primary factor for reliable pump performance.
Wash the outside of the pump thoroughly before disassembly
and all pieces prior to assembly. Cleaning parts with clean
shop solvent and air drying is usually adequate.
LUBRICATION OF MOVING PARTS
During assembly, it is imperative to provide lubrication with
clean hydraulic oil to all the running parts of the pump.
It is also necessary to coat the seals with grease. The absence
of lubrication during assembly can cause the unit to seize after
a few minutes of running.
CARE OF SURFACE TREATMENT
Be careful when handling all the internal surfaces, especially
bearings, gears, and body faces. Do not touch or score them
with metal tools or cutting edges.