PISTON AND CYLINDER ASSEMBLY MAINTENANCE - CONTINUED
Examine piston skirt and dome for score marks, cracks, damaged ring groove lands or indications of overheating.
Replace any piston if any of these conditions are present.
Using piston top ring groove gage (24), check tapered fire (top) compression ring groove (25) in piston dome. If shoul-
der A or B of gage contacts piston dome, discard dome.
Insert center tang of piston top ring groove gage (24) into fire compression ring groove (25). Hold gage at 90-degree
angle to fire compression ring groove (25) with center tang of gage in ring groove as far as it will go to prevent false
readings. There should be no contact of piston by shoulders of gage. If gage makes contact at point A or B, fire compres-
sion ring groove is worn beyond usable limits and piston dome must be discarded.
Check fire compression ring groove (25) clearance at four locations at 90 degree intervals. Measure ring land parallel to,
and at 90-degrees to, wrist pin.
Using piston second ring groove gage (26), check second (middle) compression ring groove in same way. If shoulder A
or B of gage contacts piston dome, discard dome.