Checking vacuum unit for turbocharger, biturbo — VW

Checking vacuum unit for turbocharger, biturbo
Special tools and workshop equipment required
Universal dial gauge bracket
VW 387
Hand vacuum pump
VAS 6213
or
hand vacuum pump
V.A.G. 1390
.
Turbocharger tester
V.A.G 1397A
Dial gauge set, 4-part
VAS 6341
Torque wrench
V.A.G 1783
with
open end spanner insert AF10
V.A.G 1783/1
Note
For information on how to use the
turbocharger tester
V.A.G 1397/A
refer to the operating instructions.
Ensure absolute leakproof connection of hoses to avoid measurement errors.
Ensure that the test hose is not kinked.
Pressing the memory button
M
on the
turbocharger tester
V.A.G 1397/A
causes the last measured value to be stored until the memory button
M
is pressed again or the
turbocharger tester
V.A.G 1397/A
is switched off.
Test precondition
Checking vacuum unit of turbocharger for tampering
Check sealing paint
2
at top of securing clip
1
. If the sealing paint shows signs of damage or if it has been removed completely, this is a clear indicator for tampering.
Note
On vehicles without securing clip, check the sealing paint on the adjuster nuts at the linkage of the
regulating flap potentiometer
G584
for damage.
If you suspect tampering, the repair work is not covered by the warranty.
Test procedure
Disconnect vacuum hose from vacuum unit for turbocharger
1
.
Connect
turbocharger tester
V.A.G 1397A
2
and
hand vacuum pump
VAS 6213
or
hand vacuum pump
V.A.G. 1390
3
to vacuum connection of vacuum unit
1
using a T-piece to do so.
Switch on
turbocharger tester
V.A.G 1397A
and move sliding switch on device to position II.
Note
When the end position has almost been reached, pump slower and carefully observe the linkage. The result will be falsified, if you keep on pumping after the end position has been reached.
Using the hand vacuum pump, verify that the vacuum unit for turbocharger has no leaks and that the travel mechanism is free to move. To do this, observe the linkage of the vacuum unit.
Note
The travel mechanism must start to move at a pressure of -50 … -150 mbar (as indicated on the turbocharger tester VAG 1397A). The end position must be reached at a pressure of -350 … -450 mbar.
The linkage must be free to move without catching.
Note the pressure values in mbar for the start and end of movement. These values will be required during guided fault finding.
If the linkage is not free to move, renew turbocharger.
If no vacuum is generated, renew vacuum unit for turbocharger.