COVER-DIFFERENTIAL 1990784 - Caterpillar

start by: a) remove air cleaner housing1. Put on the parking brake. Remove the pressure from the brake system by making several brake applications with the foot brakes until brake pressure gauge shows zero pressure.
Do not remove or loosen any brake lines from the accumulator until brake pressure is zero.
2. Remove the floor plate from over accumulator.3. Disconnect oil supply line (3) to brake control valve from accumulator. Remove the support bracket (1).4. Remove the mounting bolts (2) from the accumulator. Fasten a hoist to the accumulator and remove the bolts that fasten the bottom of accumulator to the frame.5. Remove the accumulator. Weight of accumulator is 110 lb. (50 kg).
Use care when moving accumulator because it contains nitrogen gas under high pressure.
Install Accumulator
1. Fasten a hoist and put the accumulator into position on the machine. Install the upper and lower mounting bolts for the accumulator.2. Install the support bracket.3. Make a connection between the oil supply line and the accumulator.4. Check the nitrogen gas pressure in the accumulator and charge if necessary. See TESTING AND CHARGING THE ACCUMULATOR in TESTING AND ADJUSTING.5. Install the floor plate.6. Check the oil level in hydraulic tank, and add oil as necessary.end by: a) install air cleaner housingDisassemble Accumulator
start by: a) remove 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 by slowly loosening the three bolts (2) that fasten the flange (4) to the accumulator head (3).2. Remove the flange (4) from head. Remove the O-ring seal from flange. The seal will be damaged when pressure is released. Replacement O-ring seals are stored in counterbore in head (3).3. Remove the bolts (1) from head. 4. Remove the piston (6) from accumulator tube by installing a 1/2"-13NC bolt (5) in the threaded hole in piston. Pull the piston out of tube.5. Remove the two seal assemblies from piston.Assemble Accumulator
1. Put clean hydraulic oil on inside walls of accumulator tube. 2. Install inner part of seal assemblies on the piston. Use expander from tool setup (A) to stretch outer part of seal assemblies.3. Install outer part of seal assemblies on the piston. Use compressor and clamp from tool setup (A) to install piston in tube. Push the piston to bottom of accumulator tube. 4. Install a new leather ring and O-ring seal on head. Install head and fastening bolts.5. Install flange with new O-ring seal on the head. Install three bolts.end by: a) install accumulatorb) charge accumulator as outlined in TESTING AND ADJUSTING