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Fuel System, Checking For Leaks

Special tools and workshop equipment required 

Connector Coupling Color Coding on Connector Coupling
Fuel supply Black
Fuel Return Line Blue
Bleeder White or beige

Evaporative Emissions Tester :KLI 9210  Preparation:

NOTE:

Depending on the version, the appearance of the :KLI 9210  may vary.

-- Check on :KLI 9210  whether there is enough fluid in the smoke generator.

-- Set the valve -D- to "Hold".

GWWN20-10395Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Open the nitrogen bottle -H-.

-- Connect the measuring hose -G- to the self-test connection -B-.

-- Set the valve -D- to "Test".

-- Using the pressure reducer -J- adjust the pressure to 25 mbar (10 in. H2 O).

-- Set the valve -D- to "Hold".

If the pressure is not maintained, check the tester.

Fuel System, Checking for Leaks:

GWWN20-10639Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the :KLI 9210/55-1  to the breather lines -A- "white markings" as illustrated.

-- Connect the measuring hose -G- on the :KLI 9210  to the :KLI9210/55-1  .

GWWN20-10640Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the :KLI 9210  to the vehicle battery.

-- Remove right rear wheel housing liner.

-- Tightly close the hose to the air filter -arrow- using a hose clamp.

GWWN20-11287Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Set the valve -D- to "Test". The fuel system is now filled.

GWWN20-10395Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Watch the pressure gauge -C- and the flow meter -E-. The fuel system is filled if the flow rate decreases and the pressure increases to 10 in. H2O (25 mbar).

-- After the pressure has stabilized, set the valve -D- to "Hold".

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

-- Set the valve -D- to "Test" and fill the system with smoke.

-- While the fuel system is being filled, press the smoke generator button -I- for approximately one minute.

The fuel system is now under pressure and filled with smoke.

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

NOTE:

Illuminate components and hoses with a strong flood light, the smoke will be more visible.

An ultrasonic sensor tester or commercially available leak spray can also be used to locate leaks.

Depending on how long fault finding lasts, the smoke generator button may need to be pressed again. This ensures there is enough smoke present in the fuel system.

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

GWWM20-0233Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Replace any leaking hoses or components.