Preparation For Test

PREPARATION FOR VACUUM TESTS:
Special Tools:

Vacuum - Pressure Tester:

Vacuum - Pressure Tester #116 589 25 21 00
Distributor #115 805 03 22

Specifications:
Permissible leaks per vacuum circuit (without vacuum reservoir):
30 mbar/min. at 400 mbar vacuum
Permissible leaks in check valves:
50 mbar in 10 min. at 300 mbar vacuum
Permissible leaks in remaining components:
20 mbar/min. at 300 mbar vacuum
Plug-on length of connections:
10-12 mm

Vacuum Circuits:
The vacuum system is subdivided into 4 test circuits. If a given trouble prevails (e.g. legroom flap not opening) the respective circuit can be tested first.
Vacuum Circuit I:
Switchover valves with red/green vacuum line.
Function selection "e", off (ignition off).
Vacuum Circuit II:
Vacuum element (38) for defroster nozzle flaps (short and long stroke) with vacuum line red/light blue and red/white, and vacuum element for center nozzle flap (40a) and vacuum line red/black.
Function selection "c", MAX. cooling - recirc air ("MIN" engaged), ignition on.
Vacuum Circuit III:
Vacuum element (39) for legroom flap with red/yellow vacuum line.
Function selection "b", MAX. cooling ("MIN" engaged), ignition on.
Vacuum Circuit IV:
Vacuum elements (42) and (43) for main air flaps with dark red vacuum lines.
Function selection "a", defrosting, ignition on.

NOTE: If a leak or functional trouble is suspected in the entire vacuum system, begin the test at the check valve (36) and the vacuum reservoir (37). Then continue testing the respective circuit until the actual fault is found.