Parker P1/PD Series User Manual

Parker Hannin Corporation
Hydraulic Pump and Power Systems Division
Marysville, Ohio USA
Bulletin HY28-2708-02/SVC/EN | July 2019
Medium Pressure Axial Piston Pumps
P1/PD B-mod Service Information
33
Compensator Disassembly
(C, L & AM B-mod control options)
NOTES:
Access plugs on end of compensator spool bores are hardened plugs.
Do not interchange with other plugs in the control.
For rotation change, the complete compensator assembly will need to
be replaced.
The Pmax spool and inner spring are NOT interchangeable with the load sense or
remote differential spools and springs.
The differential compensator spool and springs are not interchangeable with the main
pressure compensator spool and inner spring. Also, the “L” differential spool is not
interchangeable with the “AM” differential spool.
Compensator Disassembly:
1. Measure and record the extension of the two (only one for “C” control) pressure
adjusting screws.
2. Carefully remove the main compensator (Pmax) spring cap (#9) with outer spring
guide (#6). For “L” and “AM” controls, the Pmax spring cap is the larger of the
two caps. Remove the two springs (#4 & 5). Remove the inner spring guide (#3)
and the Pmax spool (#1) from the compensator housing.
3. For the “L” and “AM” controls, carefully remove the differential compensator
spring cap (#28) with the outer spring guide (#24). The load sense spring cap is
the smaller of the two caps, and the one closer to the top of the controller body.
Remove the inner spring guide (#21) and differential compensator spool (#20) from
the housing.
4. To disassemble the Pmax cap (#9) and outer spring guide (#6) assembly, thread
a long M6 screw through the hole of the Pmax cap to push the outer spring
guide out of the cap.
5. To disassemble the differential cap (#28) and outer spring guide (#24) assembly,
thread a long M6 screw threw the hole of the differential cap to push the outer
spring guide out of the cap.
6. Remove all O-ring boss access plugs (#13 & 18).
7. Remove all internal set screws and plugs (#2, 15, & 16).
NOTE: The compensator is supplied as an assembly. Some individual parts may only
be available in kits. See the controls section of this manual for details.
1. Inspect the main compensator (Pmax) spool (#1) and the differential spool (#20)
for scratches, damage, or contamination particles.
2. Inspect the springs for proper free extension length (see chart).
3. Inspect the spool bores for scratches, damage, or contamination. Apply a light
oil lm on the spool(s) and check their t in the appropriate bore. The spool
should t snugly in the bore and not have any radial play.
4. Inspect orices for any contamination particles that may be blocking the orice.
Compensator Inspection
Item No Component Description
Free Length
[mm]
Tolerance Ref. ±
[mm]
4 Pmax Inner Spring 28.85 0.66
5 Pmax Outer Spring 35 0.66
22 Differential Inner Spring 14.9 0.66
23 Differential Outer Spring 21 0.66
Reference item numbers on page 13-16.
Table 1 - P1/PD B-Mod C, L, & AM Compensator Free Spring Length
Compensator Procedures

Parker P1/PD Series Specifications

General

Brand	Parker
Model	P1/PD Series
Category	Water Pump
Language	English