784C and 785C Off-Highway Trucks Machine Systems Caterpillar

Removal Procedure

Start By:

1. Remove the cab front plate. Refer to Disassembly and Assembly, "Plate (Cab Front) - Remove and Install".

2. Release the air system pressure. Refer to Disassembly and Assembly, "Air Tanks (Brake) - Purge".

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In order to prevent possible personal injury, release the air pressure from the air tank before disconnecting any components of the air system.

Note: Cleanliness is an important factor. Before the removal procedure, the exterior of the component should be thoroughly cleaned. This will help to prevent dirt from entering the internal mechanism.

Note: Put identification marks on all hose assemblies, on all tube assemblies and on all wire harnesses for installation purposes. Plug all hose assemblies and all tube assemblies. This helps to prevent fluid loss and this helps to prevent contaminants from entering the system.

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Illustration 1	g00521324

1. Disconnect hose assembly (1) from the supply air manifold.
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   Illustration 2	g00521328

2. Disconnect hose assembly (2) from the brake double check valve.
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   Illustration 3	g00521330

3. Disconnect wire harness connector (3) from the accelerator control rotary position sensor.
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   Illustration 4	g00521331

4. Remove four bolts and washers (4). Remove the brake pedal plate (arrow).
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   Illustration 5	g00521332

5. Disconnect hose assembly (1) from elbow (5). Remove elbow (5) from the service brake air control valve.
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   Illustration 6	g00521338

6. Disconnect hose assembly (2) from elbow (6). Remove elbow (6) from the service brake air control valve.
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   Illustration 7	g00521340

7. Remove three bolts (7). Remove service brake air control valve (8) from the brake pedal plate.

Installation Procedure

Note: Apply 5P-3413 Pipe Sealant to all pipe plugs, nipples and fittings that are used during the installation procedure.

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Illustration 8	g00521340

1. Install service brake air control valve (8) with three bolts (7).
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   Illustration 9	g00521338

2. Install elbow (6) to the service brake air control valve, as shown. Connect hose assembly (2) to elbow (6).
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   Illustration 10	g00521332

3. Install elbow (5) to the service brake air control valve, as shown. Connect hose assembly (1) to elbow (5).
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   Illustration 11	g00521331

4. Install the brake pedal plate (arrow) with four bolts and washers (4).
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   Illustration 12	g00521330

5. Install wire harness connector (3) to the accelerator control rotary position sensor.
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   Illustration 13	g00521328

6. Connect hose assembly (2) to the brake double check valve.
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   Illustration 14	g00521324

7. Connect hose assembly (1) to the supply air manifold.

8. Refer to Operation and Maintenance Manual, SEBU7173, "Starting with an External Air Supply" in order to refill the air tanks.

End By:

1. Install the cab front plate. Refer to Disassembly and Assembly, "Plate (Cab Front) - Remove and Install".

2. Remove the front wheel chocks and the rear wheel chocks. Refer to Disassembly and Assembly, "Wheel Chocks (Front and Rear) - Remove and Install".