TM 5-3895-359-14&P
TROUBLE SHOOTING
SUGGESTED REMEDY
1.
Check for carbon deposits, a bent valve guide,
7.
Black carbon deposits extending from the valve
defective spring or antifreeze (glycol) in the lubricating
seats to the guides indicates cold operation due to light
oil. Replace a bent guide. Clean-up and reface the
loads or to the use of too heavy a fuel. Rusty brown
valve. Replace the valve if necessary.
valve heads with carbon deposits forming narrow collars
near the guides indicate hot operation due to overloads,
2.
Check for excessive valve-to-guide clearance,
inadequate cooling or improper timing which results in
bent valve guide or carbon deposits. Replace a bent or
carbonization of the lubricating oil. Clean-up the valves,
worn guide. Clean the carbon from the valve. Reface
guides and inserts. Reface the valves and inserts or
or replace the valve, if necessary.
replace them if they are warped, pitted or scored.
3.
Check the operating conditions of the engine for
8.
Check for a worn valve guide or excessive
overload, inadequate cooling or improper timing.
exhaust back pressure. Replace a worn guide. Check
Reface the valve and insert. Replace the valve if it is
the valve seat for improper seating. Reface the valve
warped or too badly pitted. Use a harder-face valve if
and insert or, if necessary, replace.
the operating conditions warrant.
9.
Check for a bent valve stem or guide, metal chips
4.
Check for contact between the valve head and the
or dirt, or for lack of lubrication. Clean up the valve
piston as a result of incorrect valve clearance, or a
stem with crocus cloth wet with fuel oil or replace the
defective spring. Check the valve guide, insert, cylinder
valve. Replace the guide. When installing a valve, use
head and piston for damage. Replace damaged parts.
care in depressing the spring so that the spring cap
DOES NOT scrape the valve stem.
5.
Check for excessive valve-to-guide clearance, a
defective valve spring or etching of the valve stem at
10. Check for a gear train failure or for improper gear
the weld. Improper valve clearance is also a cause of
train timing.
this type of failure. Check the guide, insert, cylinder
head and piston for damage. Replace damaged parts.
11. Check the operation of the engine for excessive
idling and resultant low engine exhaust back pressure.
6.
Replace a worn valve guide. Check and replace
Install valve guide oil seals.
the valve, if necessary.
10-2-132
