Disassembly - TM-55-1930-208-240265

TM 55-1930-208-24

4-11. PISTONS AND CONNECTING RODS - Continued.

b. Disassembly - Continued.

WARNING

To reduce the risk of injury to personnel, keep fingers out of piston pin hole when disassembling the piston dome from

the skirt.

(8) Use special tool J33048 and grasp the piston assembly by the skirt and pin area of the dome. Bring piston

assembly down onto the neoprene head of the tool with sufficient force to separate the dome (10) and skirt

(11).

(9) Remove seal ring (12) and piston pin bearing (13). Remove two bolts (14) from connecting rod.

c. Cleaning.

(1) Clean piston components with fuel oil and drywith compressed air.

(2) Remove hard carbon on piston crown with wire brush. Do not wire brush piston skirt.

(3) Clean ring grooves with suitable tool or piece of an old compression ring ground to a bevel edge.

(4) Clean inside surfaces of piston crown and skirt and oil drain holes in lower half of piston skirt.

(5) Glass beading can be used to clean piston crown. Allowable air pressure is 80-100 si (552-689 kPa). Do

not leave glass beads in the piston crown.

NOTE

Do not attempt to clean piston skirt by glass beading, as it will remove the tin plating.

WARNING

Do not breathe cleaning solvent P-D-680 vapors for long periods of time or use solvent near open

flames. To avoid illness, explosion, or fire, only use solvent in well-ventilated areas away from open

flames.

(6) Clean connecting rod and piston pin with solvent (item 4, Appendix C) and dry.

(7) Blow compressed air through the drilled oil passage in the connecting rod, to be sure orifice, oil passage, and

spray holes are not clogged.

4-32