Pressure Test; Vacuum Test - Stihl TS 700, TS 800 Service Manual

7.2.2

Pressure test

1
– Preparations,
see b 7.2.1
: Connect pressure hose (1) of
tester 1106 850 2905 to nipple of
test flange.
: Close vent screw (1) on the
rubber bulb.
0,4 0,6
0,2
0,8
0
1,0
: Pump air into the crankcase with
the rubber bulb until the gauge
indicates a pressure of 0.5 bar. If
this pressure remains constant
for at least 20 seconds, the
crankcase is airtight.
26
– If the pressure drops, the leak
must be located and the faulty
part replaced.
Note:
To find the leak, coat the suspect
area with oil and pressurize the
crankcase. Bubbles will appear if a
leak exists.
– After finishing the test, open the
vent screw on the rubber bulb
and disconnect the hose of tester
1106 850 2905.

– Vacuum test

see b 7.2.3
1
7.2.3 Vacuum test
Oil seals tend to fail when subjected
to a vacuum. In other words, the
sealing lip lifts away from the
crankshaft during the piston's
induction stroke because there is no
internal counterpressure.
An additional test can be carried
out with the vacuum pump
0000 850 3501 to detect this kind of
fault. Carry out the same
preparations as for the pressure
test, see b 7.2.2.
1
: Connect suction hose (1) of
vacuum pump 0000 850 3501 to
nipple of the test flange.
1 2
: Close vent screw (1) on the
pump.
: Operate lever (2) until the
pressure gauge indicates a
vacuum of 0.5 bar.
TS 700, TS 800