MAK M 20 - Page 57

Valve Guide / Oil Scraper Ring
Inspection / Replacement
A5.05. 01.05.01.01
15000
M20
en / 31.05.2010 IB021186 1/2
01
See also: 01.01.01.nn, 01.02.01.nn, 01.06.01.nn, 01.07.01.nn
Spare parts list: B1.05.01.2.2107
Time requirement: 1 Pers./ 0,20 h
Personnel qualification: skilled engine hand
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Operating medium: Heavy fuel
Inspection:
of valve guide clearance of inlet and exhaust valves after 15,000 h
Auxiliary material:
Molykote paste “G-Rapid Plus” **
** or a product of equal standard
Sequence of operations:
1. Replacement of the oil scraper rings
(O-rings)
1.1 Dismount valve face, thoroughly clean
stem.
1.2 Remove the O-ring (Fig. 1/1) from the
groove of the guide bush by means of a
sharp angle-shaped wire.
1.3 Clean the groove.
1.4 Slightly oil the new O-ring and carefully
insert the O-ring in the groove. The ring
must not be twisted in mounting position.
CAUTION
The O-ring is used to adjust the
lubricant quantity and must only
be replaced by a new original
MaK spare part.