T O 35C2-3-442-2
P-8-627-34
TM-07464A-35 TM 5-6115-457-34
force. Compress each spring to a length
c. Tag each intake and exhaust valve
of 1.766 inches. Force required for com-
and the cylinder number it was taken from.
pression should be 54.8 to 60.6 pounds.
d. Using suitable bushing driver,
Refer to table 1-1 for spring free length
remove bushings (29, figure 8-54) from
and valve spring O.D. If limits are not
cylinder head (38).
met, replace springs.
NOTE
Do not remove inserts (31 and 33)
d. Inspect valve guides (29, figure
unless replacement is required.
for cracks, distortion, and excessive
wear.
Check inside diameter of valve guides
(29),
e. Using a suitable extracting tool,
using suitable pilot gauges. Refer to
remove inserts (31 and 33) from cylinder
maxi-
head (38).
8-191. CLEANING.
mum allowable wear limits. If limits
are
exceeded, replace valve guides.
WARNING
e. Inspect valve seat inserts for excessive
Cleaning Solvents are flammable and
wear, pitting, cracking or improper seat
moderately toxic to skin, eyes and
angle. The proper angle for seat and valve
respiratory tract. Eye and skin
is 30 degrees. Refer to table 1-1, and
protect ion required. Good general
using a suitable micrometer, check diameters
ventilation is normally adequate.
of inlet valve seat inserts and exhaust valve
CAUTION
seat inserts. If allowable limits are
Do not use a wire brush or a grind-
exceeded, replace insert.
ing wheel when cleaning components.
f. Inspect valves (30 and 32) for cracks,
a. Place valves, valve bushings, and
pitting, distortion, or excessive wear, Use
retainers in an approved cleaning solvent
a suitable micrometer and check valve stem
and allow to soak for at least one hour.
diameter. Refer to table 1-1 for maximum
Using a stiff brush, remove all carbon
allowable wear limits. If limits are not
lacquer, and residue from parts, and dry
met, replace valve.
thoroughly.
g. Coat each valve face with a thin film
b. Remove scale from cylinder head
of Prussian blue, then rotate each valve in
using an approved cleaning solvent and a
associated valve seat. Remove valves and
stiff brush, and dry thoroughly.
examine contact pattern on each valve and
c. Clean metal components with an
valve seat, A line of contact near top and
approved cleaning solvent, and dry
around entire circumference of valve seat
thoroughly.
indicates line contact with valve. This
8-192. INSPECTION.
amount of line contact would indicate that
a. Inspect cylinder heads for cracks,
the valves and valve seats are acceptable.
damaged threads, distortion, or any
If, however, line contact is not noted to
other defect.
extend completely around the seat, or gaps
b. Inspect precombustion chambers for
in line contact appear around the seat, it
damaged threads, distortion, or cracks.
would indicate that the valves have to be
Check tightness of plug (20) on the side of
reground.
precombustion chamber.
h. Inspect valve seats (31 and 33). If
c. Inspect valve springs for damaged
valve seat does not conform to the
coils, cracks, and distortion. Check spring
8-114
Change 8
