Lycoming IO-390-D Series Maintenance Manual page 241

IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual
Inspection Item
Measure the side
clearance between the
piston rings and
piston with a feeler
gauge and straight
edge (Figure 21).
Measure the piston
ring end-gap with
feeler gauges.
Complete the "Piston
Ring End-Gap
Check" in this
chapter.
**Compare the actual measurement against the limits in the latest revision of the Service Table of Limits
- SSP-1776. Replace the piston if any of the measurements are out of tolerance.
© 2020 Avco Corporation. All Rights Reserved
March 2020
Piston Inspection Checklist (Cont.)
Checking Piston Ring Side Clearance
Actual
Top
Measurement**
compression
piston ring
SSP-1776
Actual
Second
Measurement**
compression
piston ring
SSP-1776
Actual
Oil regulating
Measurement**
piston
expander ring
SSP-1776
Actual
Top
Measurement**
compression
piston ring
SSP-1776
Actual
Second
Measurement**
compression
piston ring
SSP-1776
Actual
Oil regulating
Measurement**
piston
expander ring
SSP-1776
Figure 21
Findings/Corrective Action
Cylinder 1 Cylinder 2 Cylinder 3 Cylinder 4
72-30
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