Mercedes-Benz 603 Service Manual page 274

Replacement
1
Turn out old valve seat insert with lathe tool.
Note operating instructions for the tool.
2 Check valve guides, replace if required
(05285).
3 Measure basic bore 02.
A new valve seat insert standard dimension can
be used, when the specified overlap exists.
If the minimum overlap is not achieved, machine
basic bore for valve seat insert.
4 Turn basic bore D2 with the seat insert lathe
tool so that the bore is properly cleaned up.
5 Measure machine base bore.
6 Turn valve seat insert repair stage so that
the specified overlap is produced. Compensate
height of reworked front face, If applicable.
7 Heat up cylinder head to approx. 80° C in
water bath.
8 Supercool valve seat insert with liquid
nitrogen.
Drive home valve seat insert with suitable pilot
bar.
10 Machining valve seats (05291).
EXIT