Refacing Valves - Man D 2866 LE 401 Repair Manual

Fig. 1
Apply abrasive paste to tapered area on the valve
seat.
Oil valve guide and insert valve.
Fig. 2
Use valve refacer to reface valve seat by applying
moderate axial pressure and describing a turning
motion.
Important:
Keep valve stem and valve guide free of
abrasive paste.
Fig. 3
The valve seat must have a faultless, closed grind-
ing pattern (2).
The grinding pattern width is correct if the valve
seat insert is in order.
1 Valve tapered area
2 Valve seat
Fig. 4
1 Valve seat insert
2 Valve
3 Valve seat good
4 Valve seat too wide
Note:
Valve seats which are too wide tend to accu-
mulate coking residues,
– valves become leaky –
Valve seats that are too small prevent rapid
discharge of heat from the valve disc to the
cylinder head,
– valves burn –

Refacing valves

2
3535
2
3591
1
2821
3
1
3
2822
4
96
2
2 1
4
2