Special service tools required:
Valve cone grinding machine
Preconditions: Valve is cleaned and measured.
Inspect
Ensure that there are no crater-like burns on the valve cone. Regrinding is possible once or twice.
Caution
Grinding of the valve stem end is not permitted.
Clamp valve in valve cone grinding machine and adjust the scale to a valve cone angle of 45°. Carefully regrind the valve cone removing a small amount of material only.
Following regrinding, check whether the thickness of the valve at the edge of the valve head corresponds to the specified values. Valve seat width must also be checked and compared to the values specified in the "Technical Data".
If the dimensions do not conform to the "Technical Data", the valves must be replaced.
Inspect
The valve stem and valve sealing cone must run exactly centrally. Valves with stems which cause slapping, are bent, or are worn on one side must be replaced.
The seat angle at the valve head is 45°.
After grinding the valves, the valve indentation (I) must be checked – see operation "Installation height of valves, check". Use measuring bridge KM-301 (1) and extension (2).
