TM 9-2320-272-24-4
5-5. VALVE SEAT INSERTS MAINTENANCE (Contd)
c. Counterboring
1.
Clamp base (2) of counterbore cutter (7) to cylinder head (3) near valve insert seat bore (4). Ensure
counterbore cutter (7) is securely clamped before starting electric drill motor (1).
NOTE
Allow cutter to turn several revolutions at exact moment the
proper depth in cylinder head is reached to ensure a perfectly flat
bottom of bore for valve seats to seat.
2.
Center counterbore cutter (7) in valve seat insert bore (4) and valve guide mandrel (6).
3.
Cut counterbore (5) 0.006-0.010 in. (0.1524-0.2540 mm) deeper than valve seat insert thickness to
allow staking (peening) of cylinder head (3) to secure valve seat insert.
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure to
do so may result in injury to personnel.
1.
Blow cylinder head (3) out with compressed air.
WARNING
Drycleaning solvent is flammable and toxic. Do not use near open
flame and always have a fire extinguisher nearby when solvents
are used. Use only in well-ventilated places, wear protective
clothing, and dispose of cleaning rags in approved container.
Failure to do this may result in injury or death to personnel and/or
damage to equipment.
2.
Clean opening and ports of cylinder head (3) with brush and drycleaning solvent.
3.
Dry cylinder head (3) with compressed air.
e. Installation
CAUTION
Valve seat inserts may be installed one time only. If valve seat
insert is not properly installed the first time, a new valve seat
insert must be installed.
NOTE
Keep valve seat inserts in cold storage until ready to install in
cylinder head. Install valve seat insert very quickly so room
temperature does not have a chance to expand insert and make it
difficult to install.
1.
Drive valve seat insert (9) into valve seat insert bore (4) with valve seat insert tool until fully seated.
2.
Stake (peen) valve seat insert (10) into cylinder head (3) with valve seat insert tool and valve seat
insert staking tool.
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