TM 5-3810-295-34
Figure 14-16. Valve head rim thickness.
(4) Check wear of collect recesses. Replace if
exceed 0.0004 inch in depth with at least 1.00 inches
new collets will not fit securely in place.
between high and low points. The surfaces shall not
deviate from a true plane more than 0.0003 inch within
14-19. Overhaul
0.250 inch of any opening and total deviation of less
a. Sleeve Eroded War Holes. If the area 1/16 to 5/32
than 0.0004 inch.
of an inch from edge of water hole is not free of any
(3) Remove an equal amount of stock from the
erosion, pits, scratches or blemishes which are more
valve seat insert counterbore, as was removed during
than 0.0003 inch deep, the water hole must be sleeved
the head resurfacing operation.
as follows:
(4) Sand surface of cylinder head with an
(1) Coat sleeve, part No. 191078, with sealant
orbital sander. Do not use a disc sander or allow the
and aline in top of water passage hole. With a bushing
sander to tilt or rock.
driver and hammer, drive sleeve into proper position.
(5) Using a micrometer or vernier depth gauge
(2) File sleeve flush with top of cylinder head.
check head height. Head height must be more than
Do not damage head surface. Remove any burrs from
5.460 inches.
inside diameter of sleeve, clean all cuttings from water
(6) Check exhaust ports for flatness. Ports
passages.
shall not be out of plane more than 0.003 inch.
(3) If proper sleeve is not available, heavy wall
(7) Install new injector sleeves to maintain
copper tubing may be used. Tubing must provide 0.002-
correct injector tip protrusion.
to 0.005-inch press fit. Overall length shall be
(8) Check over-all height of assembled valve
approximately one-half inch. Inside diameter must be
springs to see if it is necessary to install spacers (one-
seven-sixteenths of an inch to allow proper water flow.
sixteenth of an inch maximum) under springs to obtain
b. Resurfacing Cylinder Head. If cylinder head has
correct assembled height. Only a one thirty-second of
been scratched, etched or worn unevenly at point of
an inch thick spacer can be used if head has not been
contact with gasket seating areas, it shall be resur-
resurfaced.
faced as follows:
c. Regrooving of Cylinder Head. If the cylinder
(1) Remove 0.005 to 0.006 inch of material at
head
one time and no more than a total of 0.030 inch.
(2)
Waviness on mounting surface must not
14-15
