Oil Seals - Stihl MS 440 Service Manual

If the vacuum reading remains
constant, or rises to no more than
0.3 bar (4.35 psi) within 20 seconds,
it can be assumed that the oil seals
are in good condition. However, if
the pressure continues to rise
(reduced vacuum in the crankcase),
the oil seals must be replaced, even
if no leaks were detected in the
pressure test.
– After finishing the test, open the
vent screw and disconnect the
hose.
– Remove the test flange.
– Install the carburetor – b 12.2.1
– Undo the muffler screws and
remove the sealing plate.
– Take out the muffler screws in
succession and refit them with
Loctite – b 16.
For further assembly of the muffler –
b 6.1
– Unscrew the plug from the
cylinder if necessary.
– Install the decompression valve,
if fitted – b 6.8
28
6.3

Oil Seals

It is not necessary to disassemble
the complete crankcase to replace
the oil seals.
Fan side:
– Remove the flywheel –
b 7.3.1
: Remove the key (arrow).
: Take out the screws (arrows) on
machines with handle heating.
– Lay the generator aside.
1
– Free off the oil seal in its seat by
tapping it with a suitable tube or a
punch.
: Apply puller (1) 5910 890 4400
with No. 6 jaws 0000 893 3711.
– Clamp the puller arms.
– Pull out the oil seal.
Take care not to damage the
crankshaft stub.
– The crankshaft sealing face and
taper must be free from grease.
Clean with standard solvent-
based degreasant containing no
chlorinated or halogenated
hydrocarbons – b 16.
– Lubricate sealing lip of oil seal
with grease – b 16.
– Thinly coat the outside of the oil
seal with sealant – b 16.
– Slip the oil seal, open side facing
the crankcase, over the
crankshaft stub.
MS 440, MS 440 C