CYLINDER HEADS DISASSEMBLY. (See Figure 9-1.)
It is desirable that each valve and port be identified so that valves
can be reinstalled in the ports from which they were removed.
Because valves, seats, and guides tend to mate during operation,
returning each valve to its corresponding port will ensure a good
fit. Furthermore, it will be easier to detect the source of unusual
valve wear caused by defective seats or valve guides.
Using valve spring compressor ST448-6, compress the valve spring (3), and remove and discard the locks
Release the tension on the valve spring, and remove the valve spring seat (2), valve spring (3), valve spring
guide (4), and exhaust or intake valve (5 or 6) from the cylinder head (7).
Place the valve in a numbered valve board for later inspection and reconditioning.
Repeat steps a through e, above, for each valve. Be sure each valve is placed in a numbered valve board.
After cleaning and inspecting the cylinder heads, carry out further disassembly as necessary in accordance
with paragraphs 9-9 and 9-10.
DISASSEMBLED CYLINDER HEAD CLEANING.
Dry cleaning solvent PD-680, Type lIl, or equivalent, is flammable,
and moderately toxic to the skin, eyes, and respiratory tract.
Assure adequate ventilation. Skin, eye, and respiratory protection
is required to avoid injury to personnel.
Compressed air used for cleaning or drying can create airborne
particles that may enter the eyes Pressure shall not exceed 30 psi
(207 kPa). Wearing of goggles Is required to avoid Injury to
Clean all disassembled parts in dry cleaning solvent P-D-680, Type III, or equivalent, and dry with
compressed air or dean shop towels as necessary.
Clean the valves as follows:
Clean all traces of carbon or varnish from the valves using glass bead method MIL-STD-852, and
glass beads MIL-G-9954 sieve 60, or finer.
Polish the valves with a buffer or crocus cloth P-C-458.
Clean the cylinder heads as follows:
Clean the fuel passages using brush ST-876, and solvent P-D-680, Type lIl, or equivalent. Flush
passages with solvent and blow dry with compressed air.
Thoroughly dean the head of all carbon deposits, varnish, and accumulated dirt. Use extreme care
when wire brushing around injector seat and valve seat areas to avoid damaging the seats.
If excessive deposits of rust or scale in the water jacket is apparent, or overheating has been a
problem, dean the water jacket in accordance with paragraph 9-11.