2003/10/01 Caterpillar

Truck Engines:

3116

3126

3126B

3126E

3176

3208

3406B

3406C

3406E

C7

C9

C-10

C-12

C-15

C-16

The "Tu-Flo 550" air compressor and the "Tu-Flo 750" air compressor should not be replaced when the air compressors experience an excessive oil leak at the cylinder head gasket. Refer to table 1 for the corresponding Caterpillar part numbers of the air compressors. 4P-3977 Cylinder Head Gasket should be used to repair the excessive oil leaks at the cylinder head gasket. This kit should only be used to repair excessive oil leaks that occur at the cylinder head gasket.

Illustration 1	g01018314

Illustration 2	g01018330

The following procedure can be used to evaluate an oil leak at the cylinder head.

1. Determine if the oil leak is excessive.

   1. An excessive oil leak (1) has oil that drips to the label. Also, an excessive oil leak (1) might have oil that drips to the ground. Refer to Illustration 1.

   2. A small amount of oil can seep from the cylinder head during normal operating conditions (2). Refer to Illustration 2.

      Note: If the oil leak is not excessive, do not change the gasket. The air compressor is still functional. Wash the air compressor periodically and monitor the air compressor periodically.

2. Verify that the oil leak originates at the air compressor. If the oil leak does not originate at the air compressor, discontinue this procedure and perform the necessary repairs in order to eliminate the source of the leak. If the oil leak originates at the cylinder head gasket on the air compressor, proceed to Step 3.

3. Take a photograph of the oil leak for later reference.

4. Remove the cylinder head and clean the gasket surfaces. Scrape the soft carbon from the cylinder head surface before installation.

5. Replace the gasket by following the instructions and torque procedures that are included with the 4P-3977 Cylinder Head Gasket .

Note: In the "part causing failure field", enter the 4P-3977 Cylinder Head Gasket. Record the serial number of the air compressor in the "claim story".

In order to ensure warranty replacement, the part number of the compressor and the serial number of the compressor must be included in the "claim story". Also, be sure to photograph the compressor for later reference. This revised repair procedure is the required method for repairing a cylinder head gasket leak on the "Tu-Flo 550" air compressor and the "Tu-Flo 750" air compressor. The entire air compressor should not be replaced in order to repair an excessive leak in the head gasket.