3
3
5
4
TM 9-4940-568-34
5-46
5-8. ENGINE COMPRESSION CHECK (CONT).
b.
Valve Sealing.
(1)
If the compression is low on one or more
non-adjacent cylinders and the pressure
cannot be increased by oiling the rings, poor
valve (3) sealing is to be suspected.
(2)
Valve (3) leakage is often audible from the
intake and/or exhaust manifold.
(3)
The parent valve seats (4) can be re-ground
to a depth of .010 in. (.254 mm). Re-ground
seats are identified with a mark on the
cylinder head (5). Service valve seats must
be installed in previously ground valve
seats, notify GS Maintenance.
