Service Manual

83PK Series
Refer to Figure 12.
Disassembly
1. Remove charge pump. (See page 80.
2. Remove end cap. (See page 82).
3. Tilt the pump on its side and drain remaining oil.
Lift out the cylinder block assembly (25).
4. Remove the pistons, springs and piston seats.
Inspection
1. Inspect the running surface of the cylinder block
and piston ends for damage, nicks or unusual
wear patterns. The running surface may show
evidence of minor abrasion. This will be normal
wear. If grooved or smeared, replace with a new
cylinder block assembly.
2. Inspect the piston springs for distortion or breaks.
If necessary, replace with a new cylinder block
kit.
3. Inspect the piston seats. Residual oil may cause
these to remain stuck to the inside of the pistons.
Assembly
1. Apply a thin layer of clean oil to the pistons and
springs.
REMOVAL, INSPECTION AND
ASSEMBLY OF THE CYLINDER
BLOCK
Figure 12. PK Pump Cylinder Block
2. Install piston seats into the end of the pistons.
3. Install springs into the pistons.
4. Install each piston, spring and seat assembly
into the cylinder block.
5. With the pump housing tilted on its side, install
the cylinder block assembly (25) with pistons
contacting the thrust bearing.
6. Install the end cap. (See page 82)
7. Install the charge pump. (See page 80)
NOTE: To check if the cylinder block as-
sembly is installed correctly, position the
pump housing vertically and support
housing at the mounting flange. Push
down on the cylinder block. The cylin-
der block must move up and down freely.
If it does not, remove the cylinder block
assembly. Place a rubber band around
the cylinder block pistons to hold them
in position during installation. Then af-
ter installation cut the rubber band and
remove it. Check cylinder block assem-
bly for spring action.
25