Cleaning - TM-10-3930-632-340095

TM 10-3930-632-34

(12) that secure the cover (9) to the cylinder block;

below the travel of the lowest piston ring where the

remove the cover and gasket (10).

cylinder is not worn. Compare this measurement with a

measurement taken about 1/4 inch below the top of the

cylinder. The maximum allowable cylinder wear (the

WARNING

difference between these two measurements) is 0.008

inch.

Dry cleaning solvent, P-D-680, used to clan parts

Replace the engine assembly if the block is

Is potentially dangerous to personnel and

cracked, or if defects cannot be repaired. Replace loose

property. Avoid repeated and prolonged skin

or damaged studs. Retap damaged threads. If a proper

contact.

Do not use near open flame or

excessive heat. Flash point of solvent Is 100 F.

piston fit cannot be attained (para 9-29), the cylinders are

- 138 F. (39 C. - 59 C.).

scratched or scored, or cylinder wear exceeds 0.008

inch, rebore the cylinders as directed in paragraph 9-42

below.

9-40.

Cleaning

Inspect the backing plate for cracks and

Remove dirt and grease deposits from the

distortion. Remove any burrs with a fine stone.

block with a putty knife.

Steam-clean the block.

Inspect the oil pressure regulating valve for

Remove greasy or gummy deposits with a cloth

scoring, wear, and other damage. Inspect the Spring for

dampened in cleaning solvent P-D-680. Clean the oil

cracks and misaligned coils. Replace damaged oil

and water passages in the block with compressed air.

pressure regulator parts.

Remove varnish deposits with a wire brush.

Clean the mounting plate and all other metal

9-42.

Reboring

parts with cleaning solvent P-D-680 and dry thoroughly.

Rebore the cylinders to 3.2700 to 3.2720 inch

diameter (0.020 inch oversize). If this is not sufficient to

9-41.

Inspection

eliminate cylinder wear or damage, rebore the cylinders

Inspect the block for cracks, damaged sealing

to 3.2900 to 3.2920 inch diameter (0.040 inch oversize).

surfaces, scored or damaged bearing seats, scored or

Maximum allowable overbore is 0.040 inch.

scratched cylinder walls, damaged threads, loose or

damaged studs, corrosion in the water jacket or other

9-43.

Reassembly and Installation

defects.

Reassembly and installation is the reverse of

Check piston fit in the cylinder bores (para 9-

removal and disassembly. Refer to figure 9-26.

29).

Check cylinder bore wear with an inside

micrometer. Measure the cylinder bore at 45 intervals

9-26