Inspection - JLG 800A Service And Maintenance Manual

RISK OF PERSONAL INJURY: COMPRESSING THE BLOCK SPRING REQUIRES
FORCE OF ABOUT 80 TO 90 LBF (350 TO 400 N). 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.
28. Turn the block over. Using a press, apply pressure on the
block spring washer (50) to compress the block spring.
Compress the spring enough to safely remove the spiral
retaining ring (51). While maintaining pressure, unwind
the spiral retaining ring (51). Carefully release the pres-
sure and remove the outer block spring washer (50),
block spring (52), and inner block spring washer (53)
from the cylinder block.

Inspection

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.
PISTON
Inspect the pistons for damage and discoloration. Discolored
pistons may indicate excessive heat; do not reuse.
M inimum
slipper fo ot
thick ness
3121628
Maximum end play
Slipper
SECTION 3 - CHASSIS & TURNTABLE
SLIPPERS
Inspect the running surface of the slippers. Replace any piston
assemblies with scored or excessively rounded slipper edges.
Measure the slipper foot thickness. Replace any piston assem-
blies with excessively worn slippers. Check the slipper axial
end-play. Replace any piston assemblies with excessive end-
play.
Minimum slipper foot thickness and maximum axial end-play
are given in the table below.
Table 3-6. Slipper Foot Thickness & End Play
Measurement
Slipper Foot Thickness
Piston/Slipper End Play
CYLINDER BLOCK
Measure the cylinder block height. Replace blocks worn
beyond the minimum height specification. Inspect the run-
ning surface of the cylinder block. Replace or resurface worn
or scratched blocks. Blocks may be resurfaced to the specifica-
tions shown in the drawing, provided resurfacing will not
reduce the block height below the minimum specification.
Table 3-7, Cylinder Block Measurements.
L Frame K Frame
mm (in.) mm (in.)
2.71 4.07
(0.11) (0.16)
0.15
(0.006)
3-25