Valve Refacing

CAUTION: Discard any excessively worn or damaged valve train parts.

Minor pits, grooves, and other abrasions may be removed. Discard valves that are severely damaged if the face runout cannot be corrected by refinishing, or stem clearance exceeds specification.





Using a micrometer, check valve stem in three places to make sure it is within specification. If the valve stem is not within specifications or if the valve is damaged, DISCARD VALVE. Minor pits, grooves or runout in the valve face may be removed by refacing.





The valve refacing operation should be closely coordinated with the valve seat reconditioning operation so that the finished angles of the valve face and the valve seat will be to specification and provide a compression-tight fit.
If valve face runout is excessive or it is necessary to remove pits and grooves, reface valve to a 45-degree angle. Remove only enough material to correct runout or to remove pits and grooves. If edge of valve head (margin) is less than 0.79 mm (1/32 inch) thick after refacing, replace valve. Lapping of valve and seat is not recommended. Remove any grooves or score marks from valve stem end and chamfer it as necessary. Do not remove more than 0.23 mm (0.010 inch) from end of valve stem. Check valve clearance after refacing valve and valve seat.