Water Couplings Can Be Damaged from Over Torquing on Certain C175 Engines {1380} Caterpillar

Electric Power Generation

C175-16 GEN SET (S/N: WYB1-UP)

Engine

C175-16 (S/N: 3A91-UP; 3B91-UP; M6A1-UP; Y3A1-UP; M6B1-UP; WYC1-UP; P6L1-UP; P5P1-UP; KWT1-UP)

C175-20 (S/N: R4F1-UP; BXR1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

Water couplings over torqued in field can damage the couplings and water tube assemblies. Rotating the coupling once teeth are engaged and retighten the bolts are other reasons that damage can occur.

Solution

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Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.

Follow the procedure below.

1. If a leaking joint is found, do not tighten the bolt to stop the leak. Drain the coolant system to ensure that there is not pressure present on the pipe joint.

2. Loosen the bolts alternatively, but do not remove the bolts.

   Note: Do not rotate the coupling with the teeth engaged. Avoid contacting the sealing lips at the pipe ends during removal.

3. Insert a tool under the casing to disengage the teeth without damaging the rubber seal. Carefully remove the coupling from the joint by sliding the coupling to the side.

4. Clean the joints and the coupling sealing lips.

5. Lightly lubricate the hardware before reinstallation.

   Note: The gap distance between the tube assemblies should be between 5 mm (0.20 inch) and 25 mm (1 inch).

   Note: Do not remove the bolts from the assemblies.

6. Ensure that the pipe ends are clean and de-burred. Mark the half width of the coupling from the center of the gap on each tube assembly.

7. Center the couplings between the marks. Adjust the pipe joint and tighten the bolts hand-tight alternatively in sequence.

8. For the 88.9 mm (3.5 inch) tubes use the following torque sequence.

   1. Tighten the bolts to 4 N·m (35 lb in).

   2. Tighten the bolts to 8 N·m (71 lb in).

   3. Tighten the bolts to 10 N·m (89 lb in).

   4. Tighten the bolts to a final torque of 12 N·m (106 lb in).

9. For the 101.6 mm (4 inch) tubes use the following torque sequence.

   1. Tighten the bolts to 4 N·m (35 lb in).

   2. Tighten the bolts to 8 N·m (71 lb in).

   3. Tighten the bolts to 10 N·m (89 lb in).

   4. Tighten the bolts to a final torque of 15 N·m (133 lb in).