Leak Detection Pump, Checking Vacuum Supply

WARNING: This page is about a different car, the 2008 Volkswagen R32. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Turbocharger tester VAG 1397A
Vehicle diagnosis, testing and information system VAS 5051B, VAS 5052 or VAS 5053
T-piece 251 201 346
6 mm diameter hose

-- Remove the right rear wheel housing liner. Refer to FRONT WHEEL HOUSING LINER .

-- Remove the vacuum line -1- from the Leak Detection Pump (LDP).

Fig 1: Identifying Turbocharger Tester V.A.G 1397A With T-Piece And 6 mm Dia. Hose

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the VAG 1397A with the T-piece and the 6 mm diameter hose between the vacuum line -1- and the LDP -2-.

-- Switch on the measuring range I (absolute pressure measurement).

-- Connect the VAS 5051B and start engine.

-- Select the Guided Fault Finding operating mode on vehicle diagnostic tester.

-- Select the "Check tank ventilation system for leaks" guided function.

-- Activate the test.

-- While the test is running, observe the display on the VAG 1397A.

The pressure must pulsate and must not rise above 0.700 bar (absolute pressure) during the test.

-- If the pressure rises above 0.700 bar during the test, the vacuum supply is too low. Check the vacuum line to the intake manifold for kinks or blockages.