120M Series 2 Motor Grader Engine Supplement Caterpillar

Removal Procedure

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Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire. To help prevent possible injury, turn the start switch off when changing fuel filters or water separator elements. Clean up fuel spills immediately.

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Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.

1. Refer to Operation and Maintenance Manual, "System Pressure Release".

2. Refer to Operation and Maintenance Manual, "Battery Disconnect Switch".

3. Turn the fuel supply to the OFF position.

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Illustration 1	g02714926

4. Use two people to remove door (1). The weight of door (1) is approximately 34 kg (75 lb).

5. Remove panel (2) .

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Illustration 2	g02714922

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Illustration 3	g02714941

6. Remove bolts (3). Loosen bolts (4) .

7. Remove bracket (5) .

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Illustration 4	g02715110

8. Remove bolt (6) and clamps (7) .

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Illustration 5	g02714958

9. Disconnect flame detection temperature sensor (8) .

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Illustration 6	g02715022

Note: Cap all hose assemblies and fittings that are disconnected to prevent fluid loss. This action will also keep contaminants out of the systems.

10. Disconnect hose assemblies (9), wire assembly (10), wire assembly (11), and hose assembly (12). Plug hose assemblies (9) with Tooling (D). Plug hose assembly (12) with Tooling (E) .

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Illustration 7	g02715418

11. Remove bolt (13) and clamp (14). Disconnect wire assembly (15) .

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Illustration 8	g02714950

12. Disconnect hose (16) .

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Illustration 9	g02715397

13. Remove nuts (16) and remove combustion head (17) .

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Illustration 10	g02715399

14. Remove combustion tube (18) and gaskets (19) .

    Note: The gaskets are not reusable. Replace with new gaskets.

15. Do not remove studs (20) .

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Illustration 11	g02715421

16. Remove spark plug (21). Remove fittings (22) and fitting (23) .

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Illustration 12	g02715424

17. Use Tooling (B) to remove O-ring seals (24) and (25) from wire assembly (15). Discard the O-ring seals.

Installation Procedure

1. Install combustion head (17) in the reverse order of removal.

   1. Apply Tooling (A) onto the threads of studs (20) and nuts (16). Tighten nuts (16) in a crisscross pattern to a torque of 23 ± 3 N·m (17 ± 2 lb ft). Tighten nuts (16) again in a crisscross pattern to a torque of 28 ± 3 N·m (21 ± 2 lb ft). Tighten nuts (16) again in a crisscross pattern to a torque of 28 ± 3 N·m (21 ± 2 lb ft).

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   Use caution when you are using isopropyl alcohol. Avoid prolonged skin contact with isopropyl alcohol. Vapors may be harmful if inhaled. Use only in a well ventilated area. Do not smoke while using isopropyl alcohol. Isopropyl alcohol is flammable. Do not use near an open flame or near welding operations. Keep isopropyl alcohol away from heated surfaces exceeding 482°C (900°F).

   Note: This connection is an electrical connection and cannot be lubricated with a petroleum-based lubricant. Isopropyl alcohol is the only approved lubrication for this connection.

   2. Lubricate new O-ring seals (24) and (25) with Tooling (C) prior to installation.

   3. Tighten fitting (23) to a torque of 60 ± 6 N·m (44 ± 4 lb ft).

   4. Tighten fittings (22) to a torque of 30 ± 2 N·m (266 ± 18 lb in).

   5. Tighten spark plug (21) to a torque of 47.5 ± 4 N·m (35 ± 3 lb ft).

   6. Apply Tooling (A) to the threads of flame detection temperature sensor (8) and install the sensor. Tighten flame detection temperature sensor (8) to a torque of 45 ± 5 N·m (33 ± 3 lb ft).

   7. Tighten hose assemblies (9) to a torque of 16 ± 2 N·m (142 ± 18 lb in).

   8. Tighten tube assembly (12) to a torque of 11 ± 2 N·m (97 ± 18 lb in).

2. Refer to Troubleshooting Manual, "ARD Ignition - Test" and Special Instructions, REHS4824, "Replacement of the ARD Combustion Head on Caterpillar Products with Clean Emissions Modules".