Heat the cylinder head to about 90°C in a water bath.
Cool the valve seat ring and drive in with a suitable rod. Machine the valve seat with a valve seat tool or with a valve seat grinder. Processing of saddles to carry out to the required size.
Then measure the valve seat runout.
In this case, a runout of more than 0.05 mm is not allowed.
Measure the valve seat width and, if necessary, adjust up to 15' and down to 60'.
Insert the valve, measure the largest distance (A).
A. Exhaust valve seat ring 173.
B. Inlet valve seat ring 172.
If necessary, replace the valve seat ring as described above. This measurement can be omitted on V8 engines.
The valves must be cleaned before processing. a Measure the valve head height and check the valve runout. When the limit value is reached, replace the valves.
Exhaust valves are filled with sodium. When disassembling, pay attention to safety precautions. Sodium-filled valves must not be melted due to the risk of explosion or recycled until the sodium has been removed. Be careful when removing sodium from valves, as sodium reacts very violently and explosively when in contact with water and aqueous solutions, and fire can occur due to the hydrogen released. Sodium can be neutralized in a solution of 2 parts alcohol and 1 part water.
Replace valve seals.
Clean the groove on the valve stem.
Replace valve cotters and valve spring cap.