TM 9-2815-225-34&P
3-35. CYLINDER HEAD AND VALVE REPAIR (Contd)
LOCATION/ITEM
ACTION
REMARKS
c. Inspection and Repair (Contd)
NOTE
Repeat step 20 for each intake and exhaust valve.
20.
Valve (13) or (14)
a. Polish with crocus cloth.
b. Inspect head of valve (13) or
Discard if damaged or if valve
(14) for cupping, cracking, pitting,
head rim thickness is less than
and wear.
0.105 in. (2.667 mm).
c. Inspect stem of valve (13) or (14)
Discard if damaged or if stem
for cracks, scoring, galling, wear
diameter is less than wear limit
or bends.
shown below.
Wear Limit .................................................................... 0.449 in. (11.405 mm)
New Minimum ............................................................... 0.450 in. (11.430 mm)
New Maximum .............................................................. 0.451 in. (11.455 mm)
d. Check collet grooves on valve
Use new valve collets (2) to check
(13) or (14) stem for wear.
grooves. Discard valve (13) or (14)
if collets fit loosely in grooves.
e. Inspect for cracks using
magnetic method:
(1) Magnetize valve (13) or (14)
Inspect area A (refer to
in coil at 100 to 300 amperes, and
illustration) and discard valve (13)
inspect with residual Magnaglo.
or (14) with more than five
If damaged, defects will show
indications, longer than 0.500 in.
around circumference of valve.
(12.7 mm), or indications spaced
closer than 0.125 in. (3.175 mm).
(2) Magnetize valve (13) or (14)
Inspect areas B, C, D, and E
by headshot magnetization at
(refer to illustration). No visible
500 to 700 amperes, and inspect
or magnetic indication is
with residual Magnaglo.
acceptable. Discard. Demagnetize
acceptable valves (13) or (14).
NOTE
Repeat step 21 for each intake and exhaust valve crosshead.
21.
Valve crosshead (22) or (28)
a. Inspect for excessive wear,
Discard if damaged.
distortion, grooving, scoring,
galling, stripped threads, broken
areas, and out-of-round.
b. Inspect for cracks using
Discard if any cracks are found.
magnetic method.
3-138
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