ARMY TM 9-2815-259-24
AIR FORCE TO 38G1-125-2
MARINE CORPS 09249A/09246A-24
Cleaning solvent is flammable and toxic to eyes, skin, and respiratory tract.
Skin and eye protection are required. Avoid repeated/prolonged contact.
Provide adequate ventilation. Failure to comply could result in serious
injury or death.
Compressed air used for cleaning can create airborne particles that may
enter the eyes. Never exceed 30 psi (207 kPa) of pressure. Eye protection
required. Failure to comply could result in serious eye damage or
Clean cylinder head in chemical hot tank if available, or with solvent and brush if hot tank
is not available. Dry cylinder head with compressed air and blow out all passages.
Check cylinder head flatness as follows:
Check cylinder head flatness with precision straightedge and feeler gage. Check
lengthwise, crosswise, and diagonally in several places.
Maximum acceptable out of flat measurements are 0.003 in. (0.08 mm) for entire
length or width of cylinder head and 0.001 in. (0.03 mm) for every 5.90 in. (150
If any measurement exceeds specifications, cylinder head must be resurfaced or
replaced. To determine if cylinder head can be resurfaced, refer to step 4 (f).
(Measure cylinder head thickness).
Measure cylinder head thickness from valve cover gasket rail-to-combustion face using
outer diameter micrometer. Minimum acceptable cylinder head thickness is 4.104 in.
(104.24 mm). Replace cylinder head if out of specifications. Refer to Figure 5-91.
Resurfacing cylinder head is only necessary if cylinder head fails cylinder
head flatness test, refer to step 4 (e).
Resurface cylinder head as follows:
Resurface cylinder head if cylinder head thickness is less than the minimum
acceptable thickness of 4.104 in. (104.24 mm). Remove only what is necessary
to restore flatness.
Combustion face surface finish (surface grind only) should be 31 - 125 micro-in.
(0.7 - 3.2 micrometers). Maximum wave depth is 0.0005 in. (0.012 mm).