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TM 5-4320-308-13
5-2.
REPAIR CYLINDER HEAD AND VALVE ASSEMBLY (Continued)
3 Replace cylinder head if any of the following
conditions exist: if the cylinder contact surface
is roughened, not level, and cannot be repaired;
if the valve seats are so worn that recutting is no
longer possible; if contact surface for cylinder
head cover is rough or damaged; or if there are
cracks between the valve seats.
4 Check that the inside diameter of each valve
guide does not exceed 0.2780 inch (7.059 mm).
5
Check that valve seat angle does not exceed 45
degrees.
6
Clean valves with diesel fuel oil and dry with
compressed air.
7
Inspect valves for warpage, burning, or other
damage.
8
Inspect valve stems for scratches, scuff marks,
or other damage.
9
Inspect valve tulips, faces, and heads for pitting,
ridges, or cracks.
10
Check that each valve stem diameter is not less
- than 0.2716 inch (6.95 mm).
11
Check that each valve head diameter is not less
than 1.200 inches (30.5 mm).
REPAIR:
1
If the inside diameter of a cylinder head valve
guide (1) exceeds 0.2780 inch (7.059 mm),
replace valve guide. Press out valve guide
using mandrel 669 347 00.
2 From cylinder head bottom, push valve guide
(1) out of cylinder head (2). Insert new valve
guide (1) into cylinder head (2). Install new
valve guide by pressing in with mandrel 669 347
00. Minimum inserting pressure is 220 inch-
pounds (245 cm. kg).
3
Ream the inside diameter of the valve guide to
0.2756 / 0.2759 inch (7.000 / 7.009 mm) using
hand reamer 612 107 00.
4
Repair defective cylinder head valve seats by
recutting with a 45 degree valve seat cutter.
Recut valve seats with valve reseating tool 612
103 00, guiding pin 612 104 00, and handle for
valve reseating tool 670 323 00.Cut until valve
seat is absolutely clean.
5-3
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