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4. Remove and discard O-ring (M48A).
5. Remove check ball seat (M46) using a 5 mm internal hex.
6. Remove check ball (M47) using a pencil magnet.
7. Using a 1/4-inch internal hex, remove plugs (M34).
8. Remove and discard O-rings (M34A).
9. Slide shuttle spool (M44) out of block.
10. Using a 10 mm wrench, loosen locknut (M16). Using a 4 mm internal hex, remove adjustment screw
(M18).
11. Remove screws (M28).
12. Remove cover (M12). Remove gasket (M14).
13. Remove spring seat (M20). Remove spring (M22).
14. Remove the pilot piston (M24).
15. Remove spring seat (M25). Remove pin (M26).
16. Remove spring (J10).
17. Remove screws (M10) and washers (M11).
18. Remove block (M1HC).
19. Remove and discard O-rings (G38), (G36) and (G42) or gasket (N240).
20. Remove 4-way valve (F32).
21. Remove and discard O-rings (F324).
Inspection
1. Inspect the control block for signs of corrosion or damage.
2. Discard any damaged or worn parts.
Service Manual
Series 51 Hydraulic Proportional Controls Service Manual
HC Controls
11009446 • Rev BA • July 2014
29