3-40.1. PISTON - MAINTENANCE INSTRUCTIONS (Cont).
Use eye protection when using compressed air.
Clean the piston components with fuel oil and dry
them with compressed air. If fuel oil does not
remove the carbon deposits, use a chemical solvent
that will not harm the piston pin bushings or the
tin-plate on the piston.
The upper part of the piston, including the compres-
sion ring lands and grooves, is not tin-plated and
may be wire-brushed to remove any hard carbon. How-
ever, use care to-avoid damage to the tin-plating on
the piston skirt. Clean the ring grooves with a
suitable tool or a piece of an old compression ring
that has been ground to a bevel edge.
Clean the inside surfaces of the piston and the oil
drain holes in the piston skirt. Exercise care to
avoid enlarging the holes while cleaning them.