621H, 623H and 627H Wheel Tractor-Scrapers Machine Systems Caterpillar

Assembly Procedure

Show/hide table

NOTICE
Keep all parts clean from contaminants. Contaminants may cause rapid wear and shortened component life.

1. Clean all parts and inspect all parts. If any parts are worn or damaged, use new parts for replacement. Lubricate the O-ring seals with the lubricant that is being sealed.
   Show/hide table

   Illustration 1	g01035512

2. Apply Tooling (B) to plug (55). Install the O-ring seal and plug (55) to valve (51).
   Show/hide table

   Illustration 2	g01035511

3. Install O-ring seal (53) to spacer (54). Install spacer (54) to steering control valve (1). Install O-ring seals (52) to valve (51). Install valve (51) to steering control valve (1).
   Show/hide table

   Illustration 3	g01035509

4. Position the O-ring seals and cover (49) onto steering control valve (1). Install bolts (50) that secure cover (49) to steering control valve (1).
   Show/hide table

   Illustration 4	g01035508

   Show/hide table

   Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

5. Install stem (48), spring (47), and shims (46) into cover (49). Install the O-ring seal and plug (45) into cover (49).
   Show/hide table

   Illustration 5	g01035506

6. Install the O-ring seals and plugs (44) to spool valve (37).
   Show/hide table

   Illustration 6	g01035505

   Show/hide table

   Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

7. Install shims (41), retainer (38), washer (42), spring (39), and retainer (43) onto spool valve (37). Install the washer and bolt (40) onto spool valve (37).
   Show/hide table

   Illustration 7	g01035503

8. Install spool valve (37) into steering control valve (1). Install valve (36) into steering control valve (1). Install valve (33), shims (34), and springs (35) into steering control valve (1).
   Show/hide table

   Illustration 8	g01035502

9. Install O-ring seals (32) onto cover (22). Install O-ring seal (31) onto valve (30). Install valve (30) into cover (22).
   Show/hide table

   Illustration 9	g01035501

   Show/hide table

   Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

10. Position cover (22) onto steering control valve (1). Install bolts (29) that secure cover (22) to steering control valve (1).
    Show/hide table

    Illustration 10	g01035499

    Show/hide table

    Illustration 11	g01035500

    Show/hide table

    Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

11. Install poppet (23), spring (24), and spacer (25) into cover (22). Install O-ring seal (26) onto retainer assembly (27). Install retainer assembly (27) into cover (22). Install nut (28). Tighten nut (28) to a torque of 50 ± 7 N·m (37 ± 5 lb ft).
    Show/hide table

    Illustration 12	g01035498

    Show/hide table

    Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

12. Install O-ring seals (20) and O-ring seal (15) onto check valve (12). Install the O-ring seal and stem (16) into check valve (12). Install O-ring seal (21) and plug (17) into check valve (12). Install check ball (19), spring (14) and spacer (18) into check valve (12). Use Tooling (A) to install retaining ring (13) into check valve (12).

13. Repeat Step 12 for check valve (11).
    Show/hide table

    Illustration 13	g01035496

14. Install check valves (11) and (12) into check and relief valve (5).
    Show/hide table

    Illustration 14	g01035494

    Show/hide table

    Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

15. Install the O-ring seals and plug (6) into check and relief valve (5). Install the O-ring seals, the rings, and valves (10) into check and relief valve (5). Install check balls (9), springs (8), the O-ring seals, and plugs (7) into check and relief valve (5).
    Show/hide table

    Illustration 15	g01160560

16. Position the O-ring seals and check and relief valve (5) onto steering control valve (1). Install check and relief valve (5) to steering control valve (1).
    Show/hide table

    Illustration 16	g01035491

    Show/hide table

    Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

17. Install strainer (4), spring (3), and plug (2) into steering control valve (1).

18. Adjust the steering control valve. Refer to Testing and Adjusting for information on adjusting the steering control valve.

End By:

1. Install the steering control valve.