TM 5-3825-229-14&P
6-4. CYLINDER HEAD AND VALVES (cont)
b. Cleaning and Inspection (cont).
(7) Check valve springs for cracks, worn ends, distortion and tension. If spring ends are worn, check lower valve
spring wear plate and valve spring retainer for wear. Check for spring distortion by placing spring on a flat
surface next to a square. Measure height of spring and rotate it against square edge to measure distortion. If
distortion exceeds 0.0787 in. (2 mm), replace spring. Check spring tension at the installed height for both the
valve open and closed position using an accurate valve spring tester. Replace any valve spring that is weak,
cracked, worn or distorted.
WARNING
Wear protective goggles when using the cleaning solvent. Avoid contact with the eyes. If contact
occurs, flush eyes with cold water for 5 minutes and seek immediate medical attention. Dry cleaning
solvent (PD-680) is both toxic and flammable. Avoid prolonged breathing of vapors. Avoid skin contact.
Use only in a well-ventilated area. Keep away from open flame. Flash point of solvent is 138°F (590C).
(8) Clean all push rods in a solvent (PD-680). On push rods with an oil passage, blow out the passage with
compressed air. Check push rod ends for wear of damage. Check push rod for bends by rolling it on a flat
surface. If push rods are bent, twisted or damaged, replace them.
(9) Check cylinder head for flatness and distortion. Use a straightedge and feeler gauge. Total incremental
flatness must be within 0.0016 in. (0.04 mm) within any 5.91 in. (150 mm) diameter area. The surface
flatness should be within 0.004 in. (0.10 mm).
6-4
