Steering Valve Service - Toro Groundsmaster
4000?D Service Manual

PRELIMINARY – For Toro Distributor and Toro Company use only.

Steering Valve Service

2
1. Steering valve housing
2. Dust seal
3. O−ring
4. Spool
5. Spring retaining ring
6. Pin
7. Sleeve
8. Centering springs/spacers
Disassembly (Fig. 72)
NOTE: Cleanliness is extremely important when
repairing steering control units. Work in a clean area.
Before disconnecting the hydraulic lines, clean the port
area of the steering valve assembly. Before disassem-
bly, drain the oil, then plug the ports and thoroughly
clean the exterior. During repairs, always protect
machined surfaces.
1. Remove the seven cap screws from the steering
valve assembly.
2. Remove end cap, geroter, spacer, geroter drive,
wear plate, seal ring and O−rings from housing (Fig. 72).
3. Remove the plug and relief valve.
Hydraulic System
8
1
3
24
23
22
21
150 in−lb
(17 N−m)
18
9. Cap screw
10. End cap
11. O−ring
12. Seal ring
13. O−ring
14. Geroter
15. O−ring
16. Spacer
5
19
20
19
13
14
15
16
17
Figure 72
4. Slide the spool and sleeve assembly from the hous-
ing.
5. Remove the thrust bearing and bearing races (2).
6. Remove the quad seal.
7. Use a small blade screwdriver to carefully pry the
dust seal from the housing. Be careful to not damage the
dust seal seat in the housing.
8. Remove the pin that holds the spool and sleeve to-
gether.
9. Carefully slide the spool out of the sleeve. The cen-
tering springs and spring retaining ring will stay with the
spool as it is removed.
Page 4 − 96
6
7
4
9
10
11
12
140 to 160 in−lb
(16 to 18 N−m)
17. Geroter drive
18. Wear plate
19. Bearing race
20. Thrust bearing
21. Plug
22. O−ring
23. Relief valve
24. Quad seal
Groundsmaster 4000−D