JLG 340AJ Service Manual - Manual (Page 203)

SECTION 5 - HYDRAULICS
3121259 – JLG Lift – 5-45
BALL GUIDE, SLIPPER RETAINER, AND HOLD-DOWN
PINS
Ensure ball guide is free of nicks and scratches, and not scored.
Examine for discoloration that may indicate excessive heat or
lack of lubrication.The slipper retainer should be flat, and slip-
pers should fit in the retainer with minimal side play. Place the
hold-down pins on a flat surface and roll them to make sure
they are straight. Discard and replace any damaged parts.
BLOCK SPRING, AND WASHERS
If cylinder kit was fully disassembled, visual inspection of the
cylinder block, spring, and washers should indicate minimal
wear. Replace if cracks or other damage are present.
CYLINDER BLOCK
Examine the running face of the cylinder block. The surface
should be smooth and free of nicks and burrs. Ensure that no
scratches or grooves exist; these may drastically reduce output
flow.
SHAFT
Check to see that the shaft and its splines are straight and free
of damage or heavy wear. Inspect the shaft surface where it
meets the shaft seal. Replace the shaft if a groove exists at the
sealing land surface where it meets the shaft seal. Clean the
sealing area with a nonabrasive material if necessary. Lubricate
the shaft with a light coat of hydraulic fluid before reassembly.
SHAFT BEARING
Clean bearing with a solvent and lubricate with hydraulic fluid.
Inspect for wear, or pitting. Rotate the bearing in your hand.
Replace if it does not rotate smoothly.
SWASHPLATE
Carefully inspect each machined surface of the swashplate for
wear. Ensure all swashplate surfaces are smooth. Inspect the
swashplate's slipper running surface for flatness and brass
transfer. Excessive brass transfer from slippers may indicate
you should replace the slippers. Check the journals for
scratches. Replace swashplate if necessary.
VALVE PLATE
Inspect the valve plate for scratches and grooves. Check the
plate for pitting along the running face. If pitting from cavita-
tion exists, replace the valve plate. Check for excess wear on
the brass running face. If you observe any discoloration or
burn marks, replace the valve plate.