Inspection

Special Tool(s)

Inspection

1. CAUTION: Do not use a caustic cleaning solution or a wire brush to clean pistons.

CAUTION: Extreme care must be used when cleaning piston ring grooves on aluminum pistons.

Clean pistons with liquid soap and warm water.

2. NOTE: Use the top compression ring to clean the top ring groove and the bottom compression ring to clean the bottom ring groove. Because the ring grooves are different designs, using the wrong compression ring to clean the wrong ring groove will damage the piston.

Break the old compression rings in half, then use the compression rings to clean the piston ring groove areas of the piston.

3. Inspect the piston ring lands, skirts, oil ring slot corners and pin bosses for scoring, scuffing or cracks. Inspect the lower inner portion of the piston ring grooves for a high step. Install new piston if any show these types of damage.





4. Using the special tool and an outside micrometer, measure the keystone piston ring groove wear of the top compression ring. If any of the measurements do not meet specification, install a new piston.

5. Using a feeler gauge, measure the intermediate compression ring and the oil control ring side clearance between the ring and ring land.





6. Measure the outside diameter of the piston pin and the inside diameter of the piston pin bore. The difference between the two readings is the piston pin-to-bore clearance. Install new any piston pin or piston not within specification.