Lycoming TEO-540-C1A Maintenance Manual page 263

TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual
Piston Inspection Checklist for TEO-540-C1A Engine Models (Cont.)
Comments:
If inspection of the piston shows the original ground surface of the piston skirt to be undamaged, the
piston is acceptable and can be re-installed.
If any of the following conditions are found on the piston, replace the piston.
• Damage or pitting, cavities, surface distortion, scoring, or discoloration
• Cracked, bent, or broken lands, scored skirts or any out-of-tolerance dimensional limits
• Piston grooves worn to the extent that high ridges are on the lower lands
• Excessive side clearance of piston rings in grooves
NOTICE: Refer to the TEO-540-C1A Illustrated Parts Catalog to identify a replacement piston and
associated rings and any new details of piston inspection.
B. Piston Ring End Gap Check:
CAUTION
(1) Lubricate the piston ring, piston, and cylinder bore with a light coating of a mixture of
15% pre-lubricant (STP or equivalent) and 85% SAE 50 mineral-base aviation-grade
lubricating oil (unless otherwise directed per the latest revision of Service Instruction No.
SI-1059).
(2) Put one of the piston rings in the cylinder in which it will be used.
(3) To square the piston ring in the cylinder bore, install the piston in the cylinder (per the
"Piston Installation" procedure in this chapter) and use a soft mallet to tap the dome end
of the piston on the inside, until the bottom of the piston skirt is flush with the end of the
cylinder barrel. Remove the piston from the cylinder per the "Piston Removal" procedure
in this chapter.
(4) Measure the piston ring end-gap with feeler gauges. Record the measurement in the
Piston Inspection Checklist. Compare the measurement with the ring end gap
measurement in the latest revision of the Service Table of Limits - SSP-1776.
(5) If necessary to increase the end-gap, carefully file the ends of the piston ring.
(6) Repeat this check for each piston ring to be used in each cylinder.
© 2018 Avco Corporation. All Rights Reserved
November 2018
DURING THE PISTON RING END-GAP CHECK, USE CARE NOT TO
SCRATCH OR SCORE THE PISTON OR CYLINDER BORE.
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