Audi Workshop Service and Repair Manuals

Adjusting vacuum unit for turbocharger Turbocharger removed

Special tools and workshop equipment required

t	Universal dial gauge bracket -VW 387-

t	Hand vacuum pump -VAS 6213-

t	Pressure control valve -VAS 6342-

t	Turbocharger tester -V.A.G 1397A-

t	Dial gauge set, 4 pieces -VAS 6341-

t	Torque wrench -V.A.G 1783-

t  Open-end spanner insert AF 10 -V.A.G 1783/1- Adjusting   Note It is only necessary to adjust the vacuum unit if the vacuum unit has been removed. l  Tightening torques → Anchor

–  Pre-adjust bypass flap -1- via nut -arrow- so that bypass flap can still just be turned by hand.

–  Secure universal dial gauge bracket -VW 387- to turbocharger -arrow-.   Note t  The dial gauge values (mm) listed here include the 1 mm preload that is initially set on the gauge. t  Dial gauge -VAS 6341/1- with dial gauge extension, 30 mm -VAS 6341/3- must align with linkage of vacuum unit. –  Attach dial gauge -VAS 6341/1- with extension, 30 mm -VAS 6341/3- and flat probe -VAS 6341/4- to universal dial gauge bracket -VW 387-. –  Set dial gauge -VAS 6341/1- to 1 mm preload. –  Set scale of dial gauge -VAS 6341/1- to 0. –  Make sure that dial gauge can move freely.

–  Turn nut -1- approx. 7 turns in direction of -arrow-. –  Turn nut -2- in direction of -arrow- until dial gauge displays 7 mm. –  Hand-tighten nut -1-. –  Set dial gauge -VAS 6341/1- to 1 mm preload. –  Set scale of dial gauge -VAS 6341/1- to 0.

–  Connect up hand vacuum pump -VAS 6213-, turbocharger tester -V.A.G 1397A- (connection II) and pressure control valve -VAS 6342- as shown in illustration. –  Switch on turbocharger tester -V.A.G 1397A- and set sliding switch to position II. –  Close pressure control valve -VAS 6342- at lever -1-.

–  Move adjuster ring -1- on hand vacuum pump -VAS 6213- to position -B- to select „pressure“.   Note The following measurements must be performed in continuous sequence. Do not allow the pressure to drop to 0 between measurements. –  Operate hand vacuum pump -VAS 6213- until turbocharger tester -V.A.G 1397A- indicates 460 +/- 5 mbar.   Note If value exceeds 460 +/-5 mbar, repeat entire measurement. –  Read off and note value indicated on dial gauge -VAS 6341/1-. –  Operate hand vacuum pump -VAS 6213- until turbocharger tester -V.A.G 1397A- indicates 650 to 700 mbar. –  Vent system via pressure control valve -VAS 6342- so that pressure reading drops to 460 +/- 5 mbar.   Note If value does not reach 460 +/- 5 mbar, repeat entire measurement. –  Read off and note value indicated on dial gauge -VAS 6341/1-. –  Add values 1 and 2 together and divide by 2. –  The result (mean value) should be 5 +/- 0.5 mm.

–  If value is higher, relieve pressure until it is 0 bar, loosen nut -1- and turn nut -2- half a turn in direction of arrow and hand-tighten nut -1-. –  Set dial gauge -VAS 6341/1- to 1 mm preload. –  Set scale of dial gauge -VAS 6341/1- to 0 and repeat measurement. –  If result (mean value) is 5 +/- 0.5 mm, tighten lock nut and repeat measurement. –  If result (mean value) is 5 +/- 0.5 mm, secure nuts with sealing paint. Sealing paint → Electronic parts catalogue.

–  Secure new locking plate -1- on linkage of vacuum unit.