C4.4 Industrial Engine Piston Height - Inspect Caterpillar

If the height of the piston above the cylinder block is not within the tolerance that is given in Specifications, "Piston and Rings", the bearing for the piston pin must be checked. Refer to Systems Operation, Testing and Adjusting, "Connecting Rod - Inspect". If any of the following components are replaced or remachined, the piston height above the cylinder block must be measured:

• Crankshaft

• Cylinder head

• Connecting rod

• Bearing for the piston pin

The correct piston height must be maintained in order to ensure that the engine conforms to the standards for emissions.

Note: The top of the piston should not be machined. If the original piston is installed, be sure that the original piston is assembled to the correct connecting rod and installed in the original cylinder.

Illustration 1	g01334423
Typical example

Illustration 2	g02351060
Typical example

1. Use Tooling (A) and Tooling (B) in order to measure the piston height above the cylinder block. Use the cylinder block face to zero Tooling (A).

2. Rotate the crankshaft until the piston is at the approximate top center.

3. Position Tooling (B) and Tooling (A) in order to measure the piston height above the cylinder block. The piston height should be measured at positions (X) or (Y). Slowly rotate the crankshaft in order to determine when the piston is at the highest position. Record this dimension. Compare this dimension with the dimensions that are given in Specifications, "Piston and Rings".