Parker Hannifin Corporation
Hydraulic Pump and
Power Systems Division
Marysville, Ohio USA
Bulletin HY28-2665-02/SVC/EN
Medium Pressure Axial Piston Pumps
P1/PD Maintenance
47
6.
Carefully remove the port block. Use caution to avoid dropping the port
plate. Note the location of the bias spring - piston assembly and the control
piston assembly. The control piston, bias piston and bias spring may remain
in pump when port block is removed. Remove and discard the three white
Teflon seals on the port block. These seals should be replaced each time the
pump is disassembled.
7.
Remove the control piston and the bias piston - spring assembly.
NOTE:
For rotation change only do not disassemble further, proceed to step 16.
8.
Remove the tapered roller bearing cone and shim from the end of the shaft.
9.
Position the pump horizontally and remove the rotating group. Avoid sepa-
rating the pistons from the barrel if possible. This will assist in identifying
damage between an individual piston and bore during component inspection.
10. Remove the drive shaft.
NOTE : For shaft change only, no further disassembly is required. Pro-
ceed to assembly procedure step 5.
11. Remove the cam by rotating it 90 degrees and carefully extracting it from
the pump housing. Note the large pocket under the cam fits on the pressure
control side of the pump housing (same side as the three seals on the hous-
ing flange). Figure 2
12. Remove the front tapered roller bearing cone.
13. If there is excessive wear or damage, remove the tapered roller bearing cup
from the bottom of the housing.
14. If completing a seal change or complete overhaul, turn the housing over and
remove the snap ring and shaft seal from the housing. Note: do not reuse the
shaft seal.
15. If there is excessive wear on the port block bearing cup, cone, or both; re-
move the tapered roller bearing cup from the port block.
16. If complete overhaul or rotation change, remove control piston and bias
piston guides. The control piston and bias piston guides are installed with
anerobic thread lock. Place the port block wih piston guides in oven at 163°
C (325° F)
NOTE: To prevent annealing of heat treated surfaces: DO NOT USE A
TORCH TO HEAT PISTON GUIDES.
Large Pocket
Pressure control
side of pump
060, 075, 100, 140 Pump Maintenance
PUMP DISASSEMBLY PROCEDURE
(continued)
