- With the valve removed, check the seat for wear, cracks, damage or uneven
contact with the valve. If the damage or contact problem is slight, the valve
may be refaced with a lapping compound and lapping tool. The compound is spread
on the seat face and the valve inserted. The valve is then ground against
the seat with the lapping tool, removing a small amount of metal and creating
a polished surface.
- If the damage or contact problem cannot be rectified by lapping, the insert
can be cut with a special seat cutter which will remove the damaged material
and cut the correct angle.
- If the seat insert is cracked, too thin, or burnt, it must be replaced.
An automotive machine shop can handle the job for you.
