ACCUMULATOR GP-HYDRAULIC 3645387 - Caterpillar

1. Remove four bolts and lockwashers (2) that hold master cylinder (1) to bracket (4). Remove gasket (3).2. Disconnect oil line (5) and remove bolts (6) that hold valve (7) to the master cylinder. 3. Connect air inlet line (16) to a pressure reducing valve (12) and an outside source of air supply of at least 10 psi (0.7 kg/cm2) (70 kPa) but not more than 100 psi (7.0 kg/cm2) (690 kPa).
When the rotochamber push rod is fully extended by the outside air pressure, the return springs will push with a force beyond 200 lb. (890 N). As a safety factor, put a wood block, approximately 4 in. (10.2 cm) long, between the master cylinder and the bracket before the retaining ring is removed.
4. Let air into rotochamber (11) slowly, so push rod (9) will become fully extended.5. The master cylinder and rotochamber will come apart far enough to permit removal of washer (10). Remove master cylinder.6. Remove snap ring (15) that holds piston (14) to the push rod. Remove the piston.7. Remove seal assembly (8) and wear ring (13). Inspect seal assembly and wear ring for damage. If damaged, use new parts for replacement.8. Check all internal parts for scratches and extra wear.9. Clean metal parts in nonflammable solvent.10. Install seal assembly (8) and wear ring (13) on piston (14).11. With push rod (9) extended, install the piston and snap ring (15).12. Put valve (7) in position on master cylinder and install bolts (6).13. Connect oil line (5). Install gasket (3).14. Install master cylinder (1) over piston and slowly let push rod be retracted.15. Install four lockwashers and bolts (2) that hold the master cylinder to bracket (4). 16. With later master cylinders, remove four bolts and lockwashers (20) that hold head assembly (21), tube assembly (19) and flange (17) to bracket (22).17. Use the procedure in Steps 3 and 4 to extend push rod (24).18. Remove snap ring (23). Remove the head assembly, tube assembly and piston (26) from the push rod.19. Remove the flange and the piston from the tube assembly.20. Check seals (18) and rings (25) for damage, If damaged, use new parts for replacement.21. Clean metal parts in nonflammable solvent.22. Install seals (18) and rings (25) on piston (26).23. Install head assembly (21) on tube assembly (19).24. Install the piston in the tube assembly and the flange (17) on the tube assembly.25. With push rod (24) extended, install master cylinder and snap ring (23).26. Let push rod be retracted slowly. Put master cylinder in position on bracket (22) and install lockwashers and bolts (20). 27. Tighten bolts in number sequence as shown to a torque of 10 lb.ft. (14 N m). Tighten bolts again in number sequence to a torque of 32 5 lb.ft. (42 7 N m). See Testing and Adjusting for air removal (bleeding) of rear wheel brake system.end by:a) install rear wheel brake rotochamber and master cylinder