TM 10-4320-310-14
6-2.
REPAIR CYLINDER HEAD AND VALVE ASSEMBLY
3
Replace cylinder head if any of the following
conditions exist: If the cylinder contact surface (2) is
roughened, not level and cannot be repaired; if the
valve seats are so worn that recutting is no longer
possible; if cylinder head cover surface (1) 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 dry cleaning solvent and dry with
compressed air.
7
Inspect valves for warpage, burning, or other
damage.
8
Inspect valve stems (3) for scratches, scuff marks, or
other damage.
9
Inspect valve tulips(4) , valve joint faces (5) and
valve heads (6) for pitting, ridges, or cracks.
10
Check that each valve stem (3) diameter is not less
than 0.2716 inch (6.95 mm).
11
Check that each valve head (6) diameter is not less
than 1.200 inches (30.5 mm).
REPAIR:
1
If the inside diameter of the valve guide (1) exceeds
0.2780 inch (7.059 mm), replace valve guide. Press
out valve guide using mandrel.
2
From cylinder head bottom (3) , 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. 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.
4
Repair defective cylinder head valve seats by
recutting with a 45 degree valve seat cutter. Recut
valve seats with valve reseating tool, guiding pin and
handle for valve reseating tool. Cut until valve seat
is absolutely clean.
6-3
