FRAME AS 2129651 - Caterpillar

Before making any tests or adjustments to the brake system, stop the machine on level ground. Permit only one man on the machine. Keep all other personnel away from the machine. Never disconnect oil lines or remove plugs in the brake circuit until the oil pressure is removed. Failure to remove this pressure will have a result of a sudden release of oil under a pressure of as high as 18,600 kPa (2700 psi). To remove the oil pressure from the brake circuit: Activate the parking brake. Stop the engine. Push on the brake pedal many times until there is no brake oil pressure.
1. Open the cover behind the operator's compartment. 2. Disconnect oil line (1) from the brake control valve. Use wire to hold the oil line to the brake accumulator.3. Fasten tool (A) and a hoist to the brake accumulator. 4. Remove bolts (2) and (4). Remove accumulator (3). The weight is 79 kg (175 lb). The following steps are for the installation of the brake accumulator.5. Fasten tool (A) and a hoist to the accumulator (3). Put the accumulator in position on its mounting brackets and install the bolts (2) and (4) that hold it.6. Connect oil line (1) to the brake control valve.7. Charge the accumulator with dry nitrogen gas. See TESTING AND CHARGING THE ACCUMULATOR in TESTING AND ADJUSTING.Disassemble & Assemble Brake Accumulator
Start By:a. remove brake accumulator
The accumulator contains nitrogen gas under high pressure. Do not try to disassemble the accumulator until the pressure has been released.
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 inlet manifold (4).5. Remove cover assembly (5) and the tube assembly as a unit. 6. Remove bolts (6) and head (7) from the accumulator assembly. 7. Remove seals (8) from the head. Check the condition of the seals and make replacements if needed. 8. Remove piston (9) from the accumulator with tooling (A). 9. Remove seal assemblies (10) from the piston. The following steps are for the assembly of the brake accumulator.10. Make sure the inside of the accumulator is clean and free of dirt and foreign material.11. Install seal assemblies (10) in the piston as shown.12. Put piston (9) in position in the accumulator as shown. Make sure threaded hole in the piston is toward the head end of the accumulator.13. Fasten tooling (A) to the piston and push the piston to the bottom of the accumulator.14. Install seals (8) on the head assembly.15. Install two 7/8 "-9 NC guide pins in the accumulator. Put clean hydraulic oil on seals (8) and put head assembly (7) in position in the accumulator.16. Install bolts (6) that hold the head assembly in position. Tighten the bolts to a torque of 950 35 N m (700 25