Fuel System Leak Detection

WARNING: This page is about a different variant/trim than selected.

The procedure "Fuel System, Checking for Leaks" is performed. Refer to FUEL SYSTEM, CHECKING FOR LEAKS .
The : KLI9210 is connected to the vehicle with the : KLI9210/55-1 .

Fig 1: Connecting Measuring Hose From Evaporative Emissions Tester KLI 9210 To Adapter For Evaporative Emission Tester KLI 9210/55-1
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-- Connect the : KLI9210 to the vehicle battery.

-- Remove right rear wheel housing liner.

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

Fig 2: Identifying Air Filter Hose

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-- Close the connection on the Leak Detection Pump -V144- with a plug -A-.

Fig 3: Identifying Plug

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-- 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 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.

It is necessary to open the installation opening in the vehicle interior -1- to check the flange on the fuel pump and fuel filter.

Fig 5: Identifying Right Cover

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-- Replace any leaking hoses or components.

After completing the work, perform the "Check EVAP canister system for leaks" guided function with the Vehicle Diagnostic Tester.