PISTON INSPECTIONSM1759382
PISTON INSPECTION
E6U011011010E02
1.Measure the piston outer diameter using the micrometer.
The measurement position is 10.0 mm {0.40 in} from the lower end of the piston and in the thrust direction.
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• If it is not within the specification, replace the piston.
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Standard piston outer diameter
87.465-87.495 mm {3.4435-3.4446 in}
2.Calculate the cylinder-to-piston clearance from the cylinder bore diameter and the piston outer diameter.
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• If the clearance is at the maximum specification or more, replace the piston or cylinder block.
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Clearance between piston and cylinder
Standard
0.025-0.045 mm {0.0010-0.0017 in}
Maximum
0.11 mm {0.0043 in}
3.Measure the piston-to-ring groove clearance along the perimeter using a feeler gauge.
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• If the clearance is at the maximum specification or more, replace the piston or piston ring.
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Clearance between piston ring and ring groove
Standard
Top: 0.005-0.08 mm {0.0020-0.0031 in}
Second: 0.03-0.07 mm {0.0012-0.0027in}
Oil: 0.02-0.06 mm {0.0008-0.0023 in}
Maximum
Top: 0.17 mm {0.0067 in}
Second, Oil: 0.15 mm {0.0059 in}
4.Measure the piston ring end gap using a feeler gauge.
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• If it is at the maximum specification or more, replace the piston ring.
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Piston ring end gap
Standard
Top: 0.14-0.24 mm {0.0056-0.0094 in}
Second: 0.34-0.44 mm {0.0134-0.0173 in}
Oil (rail): 0.15-0.40 mm {0.0060-0.0157 in}
Maximum
1.0 mm {0.0393 in}
