Pressure Test - Stihl BR 500 Service Manual

If the vacuum reading remains
constant, or rises to no more than
0.3 bar 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.
– After finishing the test, open the
vent screw and disconnect the
hose.
– Carry out pressure test, b 7.8.3
BR 500, BR 550, BR 600
7.8.3

Pressure Test

1
– Always carry out the vacuum test,
b 7.8.2, before this pressure
test.
: Connect pressure hose (1) of
tester 1106 850 2905 to nipple
(arrow) on test flange.
3
: Close the vent screw (1) on the
rubber bulb.
: Pump air into the crankcase with
rubber bulb (2) until the gauge (3)
indicates a pressure of 0.5 bar.
If this pressure remains constant for
at least 20 seconds, the crankcase
is airtight. If the pressure drops, the
leak must be found and the faulty
part replaced.
– To find the leak, coat the suspect
area with oil and pressurize the
crankcase again. Bubbles will
appear if a leak exists.
– If necessary, repeat the pressure
test.
– After finishing the test, open the
vent screw and disconnect the
hose.
– Remove the test flange.
– Remove the sealing plate.
Install in the reverse sequence.
– After completing the tests, always
install a new muffler gasket,
b 7.6
2
1
37