Man D 2840 LE 301, Repair Manual

Page: 107 / 194

1
2
3
Replacing valve seat insert
105
Removing valve seat insert
Note:
If the valve seat inserts have to be changed it is necessary to change the valve guides too, as
otherwise exact refacing of the valve seat inserts after the replacement cannot be guaranteed.
For these reasons previously mentioned the tool for removing and installing valve guides and
valve seat inserts was also designed in such a way that if this tool is used valve seat inserts can
be replaced only together with the valve guides, i.e. valve guides, however, can also be changed
alone.
Fig. 1
Use a valve seat machining tool (valve seat lathe)
to cut an approx. 3
− 4 mm wide groove in the valve
seat insert.
Insert internal puller
À
into the groove and
tighten it.
Fig. 2
Note:
To avoid damage to the cylinder head
sealing face, lay disc
Á
or similar item
under the arms
Â
of the support.
Turn threaded spindle
Ã
into the internal puller
À
,
align the arms
Â
of the support and pull out valve
seat insert by turning the nut
Ä
.
Clean contact face of the seat insert in the cylinder
head.
Fig. 3
If no valve seat machining tool is available, the
following procedure may be followed:
D
Apply circular weld bead on the valve seat
using an arc welding set (arrows)
D
then pull out valve seat insert
D
Clean contact face of the seat insert in the
cylinder head
1
2
3
4
5