PISTON INSPECTION
id011000502100
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Caution
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• If the piston is replaced, replace the piston, piston pin, and the snap ring as a single component.
1. Measure the piston outer diameter using the micrometer. Perform the inspection at the following location.
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• 10.0 mm {0.394 in} from the lower end of the piston (area with no coating on piston skirt)
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― If it is not within the specification, replace the piston.
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Standard piston outer diameter
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75.958—75.984 mm {2.9905—2.9914 in}
2. Measure the cylinder bore diameter. (See CYLINDER BLOCK INSPECTION.)
3. Calculate the cylinder-to-piston clearance from the cylinder bore diameter and the piston outer diameter.
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• If the clearance exceeds the maximum specification, replace the piston or cylinder block.
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Standard clearance between piston and cylinder
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0.031—0.049 mm {0.0013—0.0019 in}
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Maximum clearance between piston and cylinder
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0.067 mm {0.0026 in}
4. Measure the piston-to-ring groove clearance along the perimeter using a feeler gauge. For the O-ring, measure the clearance with the O-ring assembled to the piston.
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• If the clearance exceeds the maximum specification, replace the piston or piston ring.
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Standard clearance between piston ring and ring groove
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Top: 0.10—0.14 mm {0.0040—0.0055 in}
Second: 0.05—0.09 mm {0.002—0.003 in}
Oil: 0.05—0.09 mm {0.002—0.003 in}
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Maximum clearance between piston ring and ring groove
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Top: 0.16 mm {0.0063 in}
Second: 0.12 mm {0.0047 in}
Oil: 0.11 mm {0.0043 in}
