Refacing Valve Seats With Valve Seat Cutter - Mercedes-Benz Unimog 435 Service Manual

Refacing valve seats with valve seat cutter
01.8
Refacing
Disassemble cylinder head, referring to 5.1/1.
2 Check valve guides and exchange if necessary,
referring to 6.1/1.
3 Clamp cylinder head in jig.
4 Check valve seat.
Note: If valve seats show only slight traces of wear,
they can be refaced without necessitating replace·
ment of valve seat rings, provided they are not ma-
chined below their bottom limit.
See 1.2/4 for repair size.
5 Introduce pilot into valve guide so that stop of
slotted rod rests on valve guide. If necessary, press
slotted rod
~ownwards
using screwdriver, and tighten
pilot.
6 Fasten cutting tool to slide rest.
Note: Make sure that cutting tool is positioned cor·
rectly on slide rest. Release coupling nut to stop free
slide rest. Attach crank handle to arm marked 45 0 •
7 Release coupling nut (2), slip cutter over pilot
and turn screw (1) until cutting tool is positioned in
center of valve seat.
8 Press pilot support (1) downward onlo pilot,
and clamp with screw (2), making sure that knurled
ring (3) is screwed down and locking screw (4) is tight
UKD 30 402 21 42-01
352/352 A
6.2/1