C7.1 Industrial Engine Air Compressor - Remove and Install - Twin Cylinder Compressor Caterpillar

Removal Procedure

Note: Either Tooling (A) can be used. Use the Tooling that is most suitable.

Note: Put identification marks on all hoses, on all hose assemblies and on all tube assemblies for installation purposes. Plug all hose assemblies and tube assemblies. Plugging all hose assemblies and tube assemblies helps to prevent fluid loss and also helps to keep contaminants from entering the system.

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Do not disconnect the air lines until the air pressure in the system is at zero. If hose is disconnected under pressure it can cause personal injury.

1. Release the pressure from the air system. Refer to the Original Equipment Manufactures (OEM) for the correct procedure.

2. Drain the coolant from the cooling system into a suitable container for storage or for disposal. Refer to Operation and Maintenance Manual, "Cooling System Coolant - Change" for the correct draining procedure.

3. If the engine is equipped with a hydraulic pump on the rear of the air compressor, remove the hydraulic pump. Refer to the OEM for the correct procedure.

4. Use Tooling (A) in order to rotate the crankshaft so that number one piston is at the top center position on the compression stroke. Refer to Systems Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston" for the correct procedure.

   Note: The air compressor must be timed with the engine in order to minimize engine vibration.

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   Illustration 1	g01966313
   Typical example

5. Remove plug (2) from the cylinder block. Remove O-ring seal (1) from the plug.

6. Install Tooling (B) into Hole (X) in the cylinder block. Use Tooling (B) in order to lock the crankshaft in the correct position.

   Note: Do not use excessive force to install Tooling (B). Do not use Tooling (B) to hold the crankshaft during repairs.

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   Illustration 2	g01969655
   Typical example

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   Illustration 3	g02022020

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   Illustration 4	g01969454
   Typical example

7. Slide hose clamps along coolant hose (3) and coolant hose (4). Disconnect coolant hose (3) and coolant hose (4) from air compressor (6).

8. Disconnect the air line from port (5) (not shown) and air line from port (7). Ref to OEM for the correct procedure.

9. Remove banjo bolt (10) and remove sealing washers (11) (not shown).

10. Remove bolt (13) and bolt (15) from support bracket (14). Remove support bracket (14) from compressor (6) and the cylinder block.

11. Support air compressor (6). Remove nuts (18) and remove the air compressor from front housing (9).

    Note: Note the position of tube assembly (12) before removal.

12. If necessary, disconnect nut (8) (not shown) and remove tube assembly (12) from the union on the cylinder block.

13. If necessary, remove studs (17) from front housing (9).

14. If necessary, remove bolts (20) and remove plate (19). Remove O-ring seal (16) from plate (19). Refer to Illustration 4.
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    Illustration 5	g01969515
    Typical example

15. Remove O-ring seal (24) from air compressor (6).

16. If necessary, follow Step 16.a through Step 16.b in order to remove gear (21) from the crankshaft of the air compressor.

    1. Use a suitable tool in order to prevent the shaft of the compressor from rotating. Remove nut (23) and remove spring washer (22) (not shown).

    2. Use Tooling (C) in order to remove gear (21) from the crankshaft of the air compressor.

Installation Procedure

Note: Either Tooling (A) can be used. Use the Tooling that is most suitable.

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Illustration 6	g01969515
Typical example

1. If necessary, follow Step 1.a through Step 1.d in order to install gear (21) to air compressor (6).

   1. Ensure that the shaft of air the compressor is clean, free from damage, and dry. Ensure that the gear is clean, free from damage, and dry.

   2. Install gear (21) and a new spring washer (22) (not shown) to the shaft of the air compressor.

   3. Apply Tooling (D) to the threads of the shaft of the air compressor. Install nut (23) to the shaft of the air compressor.

   4. Use a suitable tool in order to prevent the shaft of the air compressor from rotating. Tighten nut (23) to a torque of 190 N·m (140 lb ft).

2. Use Tooling (E) in order to lubricate a new O-ring seal (24). Install the O-ring seal to air compressor (6).

3. Use Tooling (A) in order to rotate the crankshaft so that number one piston is at the top center position on the compression stroke. Refer to Systems Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston" for the correct procedure.

   Note: The air compressor must be timed with the engine in order to minimize engine vibration.

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   Illustration 7	g02021419

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   Illustration 8	g01970516
   Typical example

4. Ensure that Tooling (B) is installed in Hole (X) in the cylinder block. Use Tooling (B) in order to lock the crankshaft in the correct position.

   Note: Do not use excessive force to install Tooling (B). Do not use Tooling (B) to hold the crankshaft during repairs.

5. Rotate the crankshaft of the air compressor until timing Mark (Y) is within (+ / -) 6 degrees of Position (Z).
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   Illustration 9	g01969454
   Typical example

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   Illustration 10	g02087758
   Compressor oil feed tube assembly

6. If necessary, install studs (17) to the front housing. Tighten the studs to a torque of 25 N·m (221 lb in).

7. If necessary, loosely install tube assembly (12) to the connection on the cylinder block. Tighten nut (8) finger tight.

8. Align air compressor (6) with studs (17). Install the air compressor to the front housing. If necessary, rotate the crankshaft of the air compressor in order to allow the gears to align.

   Note: Ensure that timing Mark (Y) is aligned with timing Marks (Z). Refer to Illustration 8 for the correct position of timing marks.

9. Install nuts (18). Tighten the nuts to a torque of 78 N·m (58 lb ft).

10. If necessary, follow Step 10.a through Step 10.c in order to install cover (19).

    1. Use Tooling (E) in order to lubricate a new O-ring seal (16). Install the O-ring seal to cover (19).

    2. Install cover (19) to air compressor (6).

    3. Install bolts (20). Tighten the bolts to a torque of 16 N·m (142 lb in).
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    Illustration 11	g02022020

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    Illustration 12	g01969655
    Typical example

11. Position support bracket (14) onto air compressor (6). Install bolts (13) finger tight.

12. Install bolts (15) finger tight.

13. Tighten bolts (15) to a torque of 44 N·m (32 lb ft).

14. Tighten bolts (13) to a torque of 22 N·m (195 lb in).

    Note: Ensure that the air compressor is not stressed as the bolts are tightened.

15. Connect the air line to port (5) (not shown) and the air line to port (7) in the air compressor. Ref to (OEM) for the correct procedure.

16. Connect coolant hose (3) and coolant hose (4) to the air compressor. Slide hose clamps along coolant hose assemblies into the correct position.
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    Illustration 13	g01970813

17. Install new sealing washer (11) (not shown) onto banjo bolt (10). Position the banjo bolt onto tube assembly (12) and install remaining sealing washer (11). Install tube assembly (12) and tighten banjo bolt (10) finger tight.

18. Tighten banjo bolt (10) to a torque of 9 N·m (80 lb in).

    Note: Ensure that the hose assembly is not stressed during the tightening procedure of the banjo bolt.

19. Securely tighten nut (8) (not shown) for tube assembly (12).

    Note: Ensure that the tube assembly does not contact any other engine components.

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    Illustration 14	g01966313
    Typical example

20. Remove Tooling (B) from Hole (X) in the cylinder block.

21. Install a new O-ring seal (1) to plug (2). Install the plug to the cylinder block. Tighten the plug to a torque of 21 N·m (186 lb in).

22. If the engine is equipped with a hydraulic pump on the rear of the air compressor, install the hydraulic pump. Refer to the OEM for the correct procedure.

23. Fill the cooling system with coolant to the correct level. Refer to Operation and Maintenance Manual, "Refill Capacities" and Operation and Maintenance Manual, "Cooling System Coolant Level - Check" for the correct procedure.