Vacuum Test; Replacing The Oil; Seals - Stihl 009 User Manual

STIHL 009, 010, 011
3.8.2

Vacuum Test

Leakage test with vacuum pump
Oils seals tend to fail when they are
subjected to a vacuum. During the
piston's induction stroke the sealing
lip lifts off the crankshaft owing to the
lack of internal counterpressure.
An additional test can be performed
with the vacuum pump to detect this
fault. The preparations for this test are
the same as described for the pres-
sure test (3.8.1).
Connect suction hose of vacuum
pump to nipple of test flange. Then
pull out pump handle until the pres-
sure gauge indicates a vacuum of
0.5 bar. When you release the pump
handle the non-return valve automati-
cally seals the suction hose.
If the vacuum reading remains con-
stant or drops no further than 0.3 bar,
the oil seals are in good condition.
However, if the vacuum continues to
drop (down to 0 bar), the oil seals
must be replaced even if no leaks
were found in the previous pressure
test.
3.8.3 Replacing the Oil Seals
Puller 0000 890 4400 in position
The oil seals can be replaced with-
out disassembling the crankcase. To
do this, first remove the clutch (2.3.1),
flywheel (4.4.4) and the contact set
(4.4.7).The primary lead can be left on
the contact set.
Both oil seals, on the ignition and
clutch sides, can be pulled out of their
seats with puller 0000 890 4400.
Screw the No. 5 jaws to the puller and
push the jaws into the oil seal by
pressing them down lightly and turn-
ing at the same time.
Open up the jaws by turning the wing
nuts and then screw down the spindle
to pull the oil seal out of its seat.
Installation of the new oil seals is
described under 3.7.
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