Fuel System, Checking For Leaks

Special tools and workshop equipment required

Diagnostic Smoke® Machine: VAS523005

Fig 1: Smoke Tester
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Connector: VAS523005/4

Fig 2: Connector
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Adapter: VAS523005/5 , : VAS523005/6 or : VAS523005/7 (depends on the diameter of the bleeder line)

Fig 3: Connection Set
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Plug: VAS523005/8

Fig 4: Plugs
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Protective eyewear (yellow)
Diagnostic Smoke® Machine: VAS523005 operating instructions

Test Conditions:

Guided Fault Finding was performed using the Vehicle Diagnostic Tester.
The Leak Detection Pump -V144- has detected a leak.

NOTE:

The "Small leak" DTC means that the total of all leaks is equal to a leak with a diameter greater than 1.0 mm.

Diagnostic Smoke® Machine: VAS523005 , Preparing:

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Check the water separator -A- on the smoke tester. Drain the water separator if necessary.

-- Connect the pressure hose to the connection -B-.

-- Use the dipstick -D- to check if there is enough fluid in the Diagnostic Smoke® Machine.

-- Connect the power supply on the Diagnostic Smoke® Machine -C- to the jump start point on the vehicle.

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

CAUTION:

Risk of interchanging the wires.

Risk of injury from fuel spraying out.

- Wear protective eyewear.

- Wear safety gloves.

- Only disconnect the white breather line.

-- Disconnect the breather line in the engine/motor compartment -1-.

-- Check the breather line for which Connection Set must be used according to the diameter.

Fig 5: Connection Set

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Diagnostic Smoke® Machine and Adapter, Checking for Leaks:

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the Connector -A- and corresponding Connection Set -B- as shown.

-- Open the shut-off valves -C-.

-- Connect the measuring hose on the smoke tester to the hose -D-.

-- Set the valve -A- to "TEST".

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Switch on the Diagnostic Smoke® Machine -B-. The Adapter is now going to be filled with test gas.

-- Watch the pressure gauge -C- and the flow meter -D-.

If the pressure rises to 35 mbar (0.51 psi) and the ball in the flow meter sinks to >>zero<<, then there are no leaks in the Diagnostic Smoke® Machine and the Adapter and they can be used.

-- Switch off the Diagnostic Smoke® Machine.

EVAP Canister Purge Regulator Valve 1 -N80-, Checking for Leaks:

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the Adapters to the bleeder lines -1- and -2- on the vehicle as shown.

-- Connect the measuring hose on the Diagnostic Smoke® Machine to the Connector -3-.

-- Close the shut-off valve -A- (line to the EVAP canister).

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Set the valve -A- to "TEST".

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Switch on the Diagnostic Smoke® Machine. The hose to the Solenoid Valve -- will then be filled with smoke.

If the pressure rises to 35 mbar (0.51 psi) and the ball in the flow meter sinks to >>zero<<, then the EVAP Canister Purge Regulator Valve 1 -N80- has no leaks and is OK.

-- Switch off the Diagnostic Smoke® Machine.

EVAP Canister, Fuel Tank and Lines, Checking for Leaks:

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Re-open the shut-off valve -A- (line to the EVAP canister).

-- Remove right rear wheel housing liner.

Fig 6: Identifying Air Filter Hose

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Remove the hose to the air filter -arrow- from the Leak Detection Pump - V144-.

-- Fill the fuel system with smoke by setting the valve -A- to "SMOKE" and switching on the Diagnostic Smoke® Machine.

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Allow the fuel system to fill with smoke until smoke escapes from the connection -A- on the Leak Detection Pump --.

Fig 7: Identifying Plug

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- If smoke escapes, seal the connection with the Plug: VAS523005/8 .

-- Set the valve -A- to "TEST" and continue filling the fuel system.

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Watch the pressure gauge -C- and the flow meter -D-.

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

If the pressure rises to 35 mbar (0.51 psi) and the ball in the flow meter sinks below the >>0.25 mm mark<< -arrow-, then the fuel system is filled.

NOTE:

If a sporadic fault is suspected, move the lines, hoses, and the cap. If the flow meter indicates a change when a component is moved, check that component.

Depending on the fuel level in the fuel tank, it may take up to five minutes to fill with smoke.

The Diagnostic Smoke® Machine has an automatic shut-off. The Diagnostic Smoke® Machine may need to be switched on again if it shuts off.

-- Once the flow meter has stabilized, switch the Diagnostic Smoke® Machine off and check the pressure gauge.

The pressure must not drop below 30 mbar (0.44 psi) after five minutes.

If the Pressure Drops or if No Pressure Develops, then Locate the Leak as Follows:

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Set the valve -A- to "SMOKE" and fill the fuel system with smoke.

-- Check all the lines, hoses and the fuel filler cap for escaping smoke.

-- Shine a flashlight on all components and hoses, because the smoke is more visible in white light.

-- Use the laser to narrow down the location of the leak. The laser beam will >>light up<< in the smoke and be visible.

-- The smoke contains a contrast agent. The contrast agent will be visible at the location of the leak under ultraviolet light.

-- The installation opening inside the passenger compartment must be opened to check the flange on the fuel pump and fuel filter.

-- Replace any leaking hoses or components.

After completing the work, perform the Check tank ventilation system for leaks guided function with the Vehicle Diagnostic Tester.