Inspection

Special Tool:

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 the pistons with liquid soap and 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 comers and pin bosses for scoring, scuffing or cracks. Replace any piston showing these types of damage.





4. Measure keystone piston ring groove wear.
1. Install the Keystone Piston Ring Gauge.
2. Install the gauge pins in the appropriate groove.
3. Using a micrometer, measure the distance between the gauge pins. Replace any piston not within specification.





5. 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. Replace any piston pin or piston not within specification.