Figure 32. Pistons, sleeves, and connecting rod assemblies, removal and installation.
99. Piston and Connecting Rod Assemblies
to pull two 0.004 inch feeler gages
f r o m between the piston and sleeve.
Cleaning, Inspection, and Repair
R e p l a c e a piston that does not meet
a. Cleaning. Clean all parts with an ap-
t h e s e standards.
proved cleaning solvent and blow dry with
( 4 ) Measure the piston pin bore with an
c o m p r e s s e d air.
i n s i d e micrometer. The proper diame-
b. Inspection and Repair.
t e r is 1.7498 to 1.7500 inch. If the
(1) Use a grooved cleaning tool and clean
piston pin bore is worn larger than
the carbon and varnish out of the ring
1.7502 inch, replace the piston.
grooves in the piston.
(5) Roll each new piston ring complete
( 2 ) Clean the oil holes in the connecting
around in its respective groove in the
r o d s and pistons with compressed air.
piston. The fit must be free around
the entire piston circumference. If the
( 3 ) Inspect each piston for cracks, breaks,
rings are tight, they can be lapped
scoring, or other damage. Measure
s l i g h t l y with a very fine emery cloth
t h e cylinder sleeve bore with an in-
l a i d on a flat surface using a light,
s i d e micrometer. The proper distance
u n i f o r m pressure.
is 5.5625 to 5.5645 inch. Place the
p i s t o n in an inverted position about
( 6 ) Measure the new rings for proper side
2 inches down in the cylinder sleeve
clearance with the piston, Replace the
bore. The piston fit in the sleeve
piston if the groove clearance exceeds
s h o u l d require a 5 to 10 pound force
0.008 inch.
73
AGO 8498A
