TM 10-3950-672-24-2
The parent valve seats can be re-ground to a depth of
0.010 in. (0.254 mm). Re-ground seats are identified
with a mark on the cylinder head. Service valve seats
must be installed in previously ground seats (refer to
page 5-252).
Head Gasket Sealing
If the compression was found low on adjacent cylinders
and the pressure cannot be increased by oiling the rings,
the head gasket is probably leaking between the
cylinders.
Low compression on a single cylinder can be caused by
an external leak or a leak to a coolant passage.
A compression leak to the coolant will normally be
detected by loss of coolant as the coolant is blown from
the cooling system.
5-172