Heat the cylinder head to a temperature of approximately 90°C in a water bath.
Cool the valve seat ring and drive in with a suitable rod. Process the valve seat using a valve seat tool or a valve seat grinder. The saddles should be processed 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 the top to 15' and the bottom 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 may not be performed on V8 engines.
Before processing, it is necessary to clean the valves. a Measure the height of the valve plate and check the valve runout. When the limit value is reached, replace the valves.
(Original can be found on the website MERCEDESMAN.ru)
The exhaust valves are filled with sodium. Pay attention to safety precautions when disassembling. Sodium-filled valves must not be melted down due to the risk of explosion or recycled until the sodium has been removed. Be careful when removing sodium from the valves, as sodium reacts very violently and explosively when in contact with water and aqueous solutions, and a fire may 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 the valve crackers and valve spring retainer.