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TM 5-4210-220-34
2-19.
ENGINE - Continued
(8) Compress the valve spring and remove the two piece tapered valve lock (6).
(9) Release the tool and remove the spring cap (7), valve spring (8) and spring seat (9). Repeat steps 6 thru 9
for each valve, as required.
(10) Turn the cylinder head over using care to keep the valves from falling out of the head.
(11) If the valves are to be reused, number each valve to facilitate reinstallation in the same location. Withdraw
the valves from the cylinder head.
(12) Remove the cam followers and push rod assemblies as required. See para. 2-19.4.
INSPECTION
WARNING
Dry cleaning solvent P-D-680 (safety or Stoddard’s solvent) is potentially dangerous. Avoid repeated and
prolonged breathing of vapors and skin contact with the liquid. Do not use near open flame, arcing
equipment or other ignition sources. Always wear eye protection and protective clothing. The flash point
of P-D-680 is 100 to 138 deg. F (30 to 59 deg. C).
Death or serious injury could occur if compressed air is directed against the skin. Do not use compressed
air for cleaning or drying unless the pressure is/has been reduced to 30 psi (2.11 kg/cm2) or less. When
working with compressed air, always use chip guards eye protection and other personal protective
equipment.
(1) Clean the springs with dry cleaning solvent (item 10, Appendix B) and dry them with compressed air. Inspect
springs for pitting or fractures. Replace any damaged spring.
(2) Install each spring in spring tester J22738-02. Replace any spring which compresses to less than 1.80 in.
(45.7 mm) with a load of 25 lb (11.3 kg).
(3) Inspect the valve spring seats and caps for wear. Replace if worn.
(4) Examine the contact surfaces of the exhaust valve bridge guides, bridges and adjusting screws for wear and
galling. Replace excessively worn components.
(5) Inspect valve face and seats. Black carbon deposits on the face could indicate blow-by due to a faulty seat.
Deposits extending from the seats to the valve guides may result from cold operation due to light loads or
using of too heavy a grade of fuel.
(6) Rusty brown valve heads with carbon deposits forming narrow collars near the valve guides is evidence of
high temperature due to overloads, inadequate cooling or improper timing.
(7) Clean the valve stems. Inspect for scuff marks or scratches. The valve faces must be free from ridges,
cracks or pitting. If necessary reface the valves or install new valves. If valve heads are warped, replace the
valves.
(8) If there is evidence of engine oil running down the exhaust valve stem into the exhaust chamber, creating a
high oil consumption condition, replace the valve guide oil seals (see INSTALLATION following).
2-207
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