Volkswagen Workshop Service and Repair Manuals

Adjusting vacuum unit for turbocharger

Special tools and workshop equipment required

t	Universal dial gauge bracket -VW 387-

t	Hand vacuum pump -VAS 6213-

t	Pressure regulating valve -VAS 6342-

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

t	Dial gauge set, 4-part -VAS 6341-

t	Torque wrench -V.A.G 1783-

t  Open end spanner insert (10 mm) -V.A.G 1783/1- Procedure –  Detach coolant hose -2- from engine cover panel.

–  Pull oil dipstick out. –  Unscrew bolts -arrows- and remove engine cover panel. –  Remove air filter housing → Chapter.

–  Unscrew bolts -arrows- and remove heat shield for turbocharger. –  Unscrew bolts -2- and remove retaining clip -1-.

–  Pull connector -3- off charge air pressure sender -G31-. –  Release catches -arrows- and pull air pipe first off throttle valve module -J338- and then off turbocharger. –  Lay hoses at air pipe to side.

–  Unscrew bolt -4- and remove crankcase breather hose from turbocharger -arrow- and lay it to side.   Note The positions labelled -1, 2, 3- should be disregarded.

–  Clamp off coolant hoses using hose clips -3094- as illustrated. –  Remove bolts -1, 3, 4, 5-. –  Pull coolant lines off turbocharger and lay to side.   Note The position labelled -2- should be disregarded.

–  Unscrew bolts -2- and -3-, then remove retaining plate.   Note The positions labelled -1- and -4- should be disregarded.

–  Remove hose -2- from turbocharger vacuum unit.   Note The position labelled -1- should be disregarded. –  Connect test and measuring instruments together as illustrated and connect to connection „II“ of turbocharger tester -V.A.G 1397A- and to turbocharger vacuum unit.

–  Close lever -1- on pressure regulating valve -VAS 6342-. –  Move slide ring -2- of hand-operated vacuum pump -VAS 6213- in direction of -arrow-. –  Switch on turbocharger tester -V.A.G 1397A- and set sliding switch to position „II“. –  Operate hand vacuum pump -VAS 6213- several times until a pressure of approx. 800 mbar is attained.   Caution Excessive pressure may damage the vacuum unit. The pressure must not exceed 800 mbar!

–  Vent hand-operated vacuum pump -VAS 6213--arrow A- so that rod of charge pressure control vacuum unit in turbocharger can move freely. –  Repeat process 5 times. –  Secure universal dial gauge bracket -VW 387- to turbocharger as illustrated.

–  Secure dial gauge -VAS 6341/1- with flat pickup -VAS 6341/4- to universal dial gauge bracket -VW 387-. –  Set dial gauge -VAS 6341/1- to 1 mm pretension at 0 bar. –  Turn graduated scale of dial gauge -VAS 6341/1- to „0“. –  Operate hand vacuum pump -VAS 6213- several times until pressure of 385 mbar is attained on turbocharger tester -V.A.G 1397A-.

Specification on dial gauge -VAS 6341/1-: 1 mm stroke.   Note t  If specification is not attained, loosen lock nut -4-. t  Lever up securing clip -2- and pull threaded piece -1- off operating lever pin -3-. t  Turn threaded piece on operating rod until specification is attained. Position threaded piece onto operating lever pin to perform check. t  Secure threaded piece with securing clip -2- to operating lever pin and tighten lock nut -4-. Checking adjustment of vacuum unit –  Set dial gauge -VAS 6341/1- to 1 mm pretension at 0 bar. Measurement 1: –  Operate hand vacuum pump -VAS 6213- several times until a pressure of 750…800 mbar is attained on turbocharger tester -V.A.G 1397A-. –  Reduce pressure to 375 mbar on pressure regulating valve -VAS 6342-. –  Read stroke on dial gauge -VAS 6341/1- and make a note. –  Reduce pressure to 0 mbar on pressure regulating valve -VAS 6342-. –  Operate hand vacuum pump -VAS 6213- several times until pressure of 375 mbar is attained on turbocharger tester -V.A.G 1397A-. –  Read stroke on dial gauge -VAS 6341/1- and make a note. –  Calculate average by adding values „1“ and „2“ and dividing sum by 2. Specification: 1 mm Measurement 2: –  Operate hand vacuum pump -VAS 6213- several times until a pressure of 750…800 mbar is attained on turbocharger tester -V.A.G 1397A-. –  Reduce pressure to 475 mbar on pressure regulating valve -VAS 6342-. –  Read stroke on dial gauge -VAS 6341/1- and make a note. –  Reduce pressure to 0 mbar on pressure regulating valve -VAS 6342-. –  Turn graduated scale of dial gauge -VAS 6341/1- to „0“. –  Operate hand vacuum pump -VAS 6213- several times until pressure of 475 mbar is attained on turbocharger tester -V.A.G 1397A-. –  Read stroke on dial gauge -VAS 6341/1- and make a note. –  Calculate average by adding values „1“ and „2“ and dividing sum by 2. Specification: 5 mm –  If specifications are not attained, repeat adjustment procedure. Specified torques → Chapter. Specified torque of heat shield for turbocharger: 8 Nm Assembly is performed in the reverse order of removal.