CYLINDER & SEAL GP-STICK 3412802 - Caterpillar

To prevent possible personal injury, make sure all cushion hitch components are completely lowered, the pressure from the hydraulic system is released and the engine has been shut off for a minimum of five minutes to be sure that the accumulator oil pressure is zero. The accumulator is filled with dry nitrogen. Do not loosen or remove the valve from the cap on top of the accumulator. A bleed screw at the bottom of the accumulator can be used to release any pressure that remains in the system.
1. Disconnect hose (2) from block (1) to drain the oil from the accumulator.2. Remove the bolts, and disconnect block (1) from the accumulator. 3. Fasten tooling (A) and a hoist to the accumulator as shown.4. Remove bolt (4) and bracket (5). Remove two bolts (behind accumulator). Remove accumulator (3). Weight is 74 kg (163 lb.). Use the reverse procedures of Steps 1 through 4 for the installation of the accumulator.Disassemble Accumulators (Cushion Hitch)
START BY:a. remove accumulators (cushion hitch) 1. Release the nitrogen gas pressure from the accumulator. Turn valve assembly (3) slowly to release the nitrogen.2. Disconnect tube assembly (1) from the manifold.3. Remove manifold (2). Check the condition of the O-ring seal behind the manifold. If the seal has damage, use new parts for replacement. 4. Remove bolts (4), cover assembly (5) and the tube assembly as a unit. 5. Remove bolts (6) and head (7) from the accumulator assembly. 6. Remove seals (8) from the head. Check the condition of the seals. If the seals have damage, use new parts for replacement. 7. Remove piston (9) from the accumulator with tooling (A). 8. Remove seal assemblies (10) from the piston.Assemble Accumulators (Cushion Hitch)
1. Make sure the inside of the accumulator is clean and free of dirt and foreign material. 2. Install seal assemblies (1) in the piston as shown. 3. Put piston (2) in position in the accumulator as shown. Make sure the threaded hole in the piston is toward the head end of the accumulator.4. Fasten tooling (A) to the piston, and push the piston to the bottom of the accumulator. 5. Install seals (3) on the head assembly. Install the back-up ring next to the flange of the head and the O-ring seal away from the flange.6. Install two 7/8"-9 NC guide pins in the accumulator as shown. Put clean hydraulic oil on seals (3), and put head assembly (4) in position in the accumulator. 7. Install bolts (5) that hold the head assembly in position. Tighten the bolts to a torque of 750 80 N m (550 60 lb.ft.). 8. Put cover assembly (6) and the tube in position on the accumulator, and install bolts (7). 9. Install manifold (8) on the accumulator. Connect tube (9) to the manifold.10. Use tool group (B), and fill the accumulators with dry nitrogen.11. For more information, see Testing And Adjusting, Form No. SENR4151.END BY:a. install accumulators (cushion hitch)