Challenger 35, Challenger 45 and Challenger 55 Agricultural Tractors Machine Systems Caterpillar

Disassembly Procedure

Start By:

1. Remove the brake valve. Refer to Disassembly and Assembly, "Brake Valve Assembly - Remove" for the machine that is being serviced.

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Illustration 1	g00566688

1. Remove the bolt and copper washer (1). Remove the reservoir cap (2) and gasket (3). Drain any oil remaining in the valve assembly.

2. Remove supply hose (4) .

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Personal injury can result from parts and/or covers under spring pressure. Spring force will be released when covers are removed. Be prepared to hold spring loaded covers as the bolts are loosened.

3. Remove the two bolts (6) and separate master cylinder body (5) from booster (7) .

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4. Remove the dust cover (8), the return spring (12), the piston (11) and plunger (10) from booster (7). Use a screwdriver that has a blade that is rounded in order to squeeze seal (9). Squeeze the seal until the blade can be inserted under seal (9). Release seal (9) in order to slide the seal off the plunger (10) .

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5. Remove O-ring seal (14), shims (13) and master cylinder plunger (15) from master cylinder body (5) .

   Note: Shims (3) are a factory assembly in order to give the required clearance between the plunger and the piston. The exact amount of shims must be retained for the reassembly.

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6. Use a screwdriver in order to lift the leaf,which is located at the tip of the screwdriver, on spring retainer (16). Pull the spring assembly from the master cylinder plunger (15) .

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7. Compress spring (17) to free valve stem (18) from the key hole in spring retainer (16) .

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8. Remove valve stem (18). Check the valve stem seal (21) for wear or damage. If necessary, replace the valve stem seal. Remove the conical washer (20), spacer (19) and spring (17) .

9. Use the same procedure as Step 4 in order to remove seal (22) from the master cylinder plunger (15) .

10. Examine the booster and master cylinder bores for visible score marks. Check that the bores are smooth to touch. Examine all pistons and plungers in the same way.

    Note: If there is any question about the condition of the parts of the master cylinder replace the unit.

11. Inspect all the other components in order to verify that all the components function properly.

12. Thoroughly clean the parts and dry the parts before reassembly.