Fuel System, Checking For Leaks, With Fuel Tank Leak Detection

Special tools and workshop equipment required 

• Evaporative Emissions Tester:KLI9210DLX 
• Adapter Hose:KLI9210/55-1  or :KLI9210/55-2  (depending on the diameter of the bleeder line)
• Hose Clamps - Up To 25 mm:3094 

:KLI9210DLX  Preparation:

-- Check on the :KLI9210DLX  whether there is enough fluid in the smoke generator.

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

Fig 1: Checking Evaporative Emissions Tester KLI 9210 DLX To Determine Whether There Is Enough Fluid In Smoke Generator

Courtesy 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 10 mbar (0.15 psi) (10 in. H₂ O).

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

• The pressure must now be maintained for a minimum of two minutes.

If the pressure is not maintained, check the tester.

Fuel System, Checking for Leaks:

Fig 2: Connecting Adapter For Evaporative Emission Tester KLI 9210/55-1 To Ventilation Line

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the : KLI9210/55-1  or :KLI9210/55-2  to the breather lines -A- "white markings" as illustrated.

-- Connect the measuring hose -G- from the :KLI9210DLX  to the Adapter Hose.

Fig 3: Connecting Measuring Hose From Evaporative Emissions Tester KLI 9210 To Adapter For Evaporative Emission Tester KLI 9210/55-1

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the :KLI9210DLX  to the vehicle battery.

-- Remove right rear wheel housing liner.

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

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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

Fig 4: Checking Evaporative Emissions Tester KLI 9210 DLX To Determine Whether There Is Enough Fluid In Smoke Generator

Courtesy 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".

• The pressure must not drop below 8 in. H2O (20 mbar) after five minutes.

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.

-- 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. Refer to FUEL DELIVERY UNIT COVER, REMOVING AND INSTALLING .

-- Replace any leaking hoses or components.