K 2500 Truck 4WD V8-454 7.4L VIN J SFI (1997)
Piston: Testing and Inspection
Clean and Inspect
CLEANING
1. Remove all varnish and carbon deposits. Do not use a wire brush.
2. Use an approved cleaning solution in order to remove the carbon build-up.
3. Remove the carbon from the ring grooves. Use a ring groove cleaning tool.
4. Clean the oil-control ring groove holes.
INSPECTION
1. Inspect the piston pin bore and the connecting rod bore for scuffing and burrs.
2. Inspect the connecting rod for damage. If a suitable jig is available, check the connecting rod for a bent or twisted condition.
3. Inspect the piston components for the following conditions:
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Scratches, scuffing, and burrs
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The ring land for cracking and wear.
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The ring grooves for burrs and nicks The skirts and the pin bosses, for cracking.
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The skirts for scuffing.
4. Inspect the connecting rod bearings for scratches or deep pitting.
MEASURING
1. Measure the piston pin diameter.
2. Measure the piston pin to piston clearance as follows:
(1) Measure the piston pin hole diameter.
(2) Subtract the piston pin diameter from the piston pin hole diameter in order to obtain the clearance.
(3) Replace the piston and the piston pin if the. clearance exceeds the specifications. The piston and the piston pin are a matched set and not
available separately.
