Service Manual
Groundsmaster 4100--DHydraulic System Page 4 -- 64
Piston Pump Control Assembly
1. Plug
2. O--ring
3. Retaining ring
4. Spring retainer
5. Spring
6. Spool valve
7. Control housing
8. Input shaft
9. O--ring
10. Wiper seal
11. O-- ring
12. Adaptor
13. Ball
14. Pin
15. Neutral switch
16. O--ring
17. Set screw
18. Set screw
19. Pin
20. Retaining ring
21. Feedback link
22. Dowel pin
23. Bell crank
24. Set screw
Figure 51
12
16
11
17
15
14
9
7
4
6
24
22
21
20
19
18
5
10
8
13
23
4
3
2
1
28 to 34 in--lb
(3.2 to 3.8 N--m)
17 to 26 in--lb
(2 to 3 N--m)
44 to 52 ft--lb
(60to70N--m)
Loctite #242
Loctite #222
Disassembly -- Manual Servo Control Assembly
1. Remove wiper seal with screw driver. Remove set
screw (18) that retains input shaft and remove input
shaft from control housing. Remove o--ring from shaft.
2. Remove set screw (24) from plug that retains valve
spool. Remove plug from control housing and o--ring
from plug.
3. Remove retaining ring (20) from pin that retains feed-
back link and spool valve. Remove pin, feedback link,
spool valve, and bell crank from control housing.
4. Compress spring and remove retaining ring ( 3). Re-
move spring retainer, spring, and second spring retainer
from spool valve.
5. Clean all parts and lubricate in clean hydraulic oil for
reassembly.
Reassembly -- Manual Servo Control Assembly
1. Install s pring retainer, spring, and second spring re-
tainer onto spool valve. Compress spring to allow retain-
ing ring (3) to be installed onto spool valve.
2. Install spool valve into control housing making sure
that metering notches on spool valve can be seen in the
metering ports.
3. Position bell crank in housing. Slide feedback link
into position between clevis on valve spool, aligning
holes, and install dowel pin and retaining ring (20).
4. Install new o--ring (9) onto input shaft. Hold bell crank
in position with feedback link slot and align splined hole
of bell crank with input shaft cavity. Install input shaft into
control housing and bell crank.
5. Apply Loctite #242 or equivalent to set screw (18)
and install into control housing. Adjust set screw until it
bottoms out on input shaft and back out one--quarter
turn.