Gaskets And Seals - BMW 5251 Service Manual

General
Table
a.
General bolt tightening torques in Nm
(max. permissible)
Bolt Class (according to DIN
267)
Gaskets and seals
Gasket aredesigned to crush and become thinner as the mat-
ing parts are bolted together. Once agasket has been used, it
is no longer capable ; f malting as good a seal as when new,
and is much more likely to leak. Forthis reason, gaskets
should not be reused.
Some gaskets and seals are d~rectional. Make sure thatthese
are ~nstalled correctly. In places where a shaft must pass
through a housing, flex~ble lip seals are used to keep the lubri-
cating
011
or grease from leaking out past the rotatlng shaft.
Seals should never be reused once they have been removed.
When rernovlng a seal, be careful not to damage the metal
surfaces.
The ltey to seal installation is to get the seal in straight without
damaging it. Use a seal driver that is the same diameter as
the seal housing to gently and evenly install into place. If a
proper size seal driver is not available, a socket of the right
size will do.
Some seals are directional and special installation instruc-
tions apply. Make sure a seal is installed with the lip facing the
correct way. Note the installation direction of the old seal be-
fore removing it.