JLG 340AJ Service Manual - Manual (Page 202)

SECTION 5 - HYDRAULICS
5-44 – JLG Lift – 3121259
NOTE: Servo (E100) is available as an assembly only. Seals (E025)
and slider block (E015) are available as repair items.
CYLINDER KIT
1. Pull to remove the slipper retainer (C20) with the pistons
(C10) from the cylinder kit.
NOTE: The pistons are not selectively fitted, however units with
high hourly usage may develop wear patterns. Number the
pistons and bores for reassembly if they are to be reused.
2. Remove the ball guide (C15).
3. Remove the three pins (C25).
BLOCK SPRING REMOVAL
NOTE: Most repairs do not require block spring removal. Perform
the following only if you suspect problems with the block
spring.
1. Turn the block over. Using a press, apply pressure on the
block spring washer (C35) to compress the block spring
(C30). Compress the spring enough to safely remove the
spiral retaining ring (C45).While maintaining pressure,
unwind the spiral retaining ring. Carefully release the
pressure and remove the outer block spring washer,
block spring, and inner block spring washer (C40) from
the cylinder block.
RISK OF PERSONAL INJURY: COMPRESSING THE BLOCK SPRING REQUIRES
ABOUT 350 TO 400 N [80 TO 90 LBF]. USE A PRESS SUFFICIENT TO MAINTAIN
THIS FORCE WITH REASONABLE EFFORT.
ENSURE THE SPRING IS SECURE BEFORE ATTEMPTING TO REMOVE THE SPIRAL
RETAINING RING. RELEASE THE PRESSURE SLOWLY AFTER THE RETAINING
RING IS REMOVED.
Inspection
OVERVIEW
After disassembly, wash all parts (including the end-cap and
housing) thoroughly with clean solvent and allow to air dry.
Blow out oil passages in the housing and endcap with com-
pressed air. Conduct inspection in a clean area and keep all
parts free from contamination. Clean and dry parts again after
any rework or resurfacing.
PISTONS AND SLIPPERS
Inspect the pistons for damage and discoloration. Discolored
pistons may indicate excessive heat; do not reuse.
Inspect the running surface of the slippers. Replace any piston
assemblies with scored or excessively rounded slipper edges.
Replace any piston assemblies with excessively worn slippers.
Check the slipper axial end-play. Replace any piston assem-
blies with excessive end-play.