Fuel System Leak Test

WARNING: This page is about a different car, the 2009 Volkswagen Rabbit, 2008 Volkswagen Rabbit, 2007 Volkswagen Rabbit, and 2006 Volkswagen Rabbit. However, it is still accessible from the selected car via links, so may be relevant.

Test Conditions

Procedure for "Fuel System, Checking for Leaks" was performed. Refer to FUEL SYSTEM, CHECKING FOR LEAKS .
The evaporative emissions tester KLI 9210 and the adapter for evap. tester KLI 9210/55-1 are still connected to the vehicle

Fig 1: 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 evaporative emissions tester KLI 9210 to the vehicles battery.

-- Remove the rear right wheel housing liner.

-- Clamp off the hose between the leak detection pump -V144- and air filter using a hose clamp up to 25 mm dia.3094 -arrow-.

Fig 2: Clamping Off Hose Between Leak Detection Pump (LDP) V144 And Air Filter

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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

Fig 3: Identifying Evaporative Emission (EVAP) Canister Purge Regulator Components

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Observe the pressure gauge -C- and flow meter -E-. If the flow quantity decreases and pressure increases to 10 in. H2O, then the fuel system is full.

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

After 5 minutes the pressure must not drop below 8 in. H2O (20 mbar).

-- If the pressure no longer decreases, replace the leak detection pump.

If the pressure is not maintained for a minimum of 5 minutes or if no pressure is built up, localize the leak as follows:

-- Fill the fuel system with smoke by setting valve -D- to "Test".

-- 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 filling with smoke.

-- Check all fuel system lines and hoses for escaping smoke. Also check the fuel tank filler tube cap.

NOTE:

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

To check for leaks at accessible locations, also use a ultrasonic measuring device or commercially available leak detection spray.

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

To check the fuel pump and fuel delivery unit flange, the assembly openings in the vehicle interior must be opened.

-- Replace any leaking hoses or components.

After completing the work, perform the "Check tank ventilation system for leaks" guided function using the vehicle diagnostic tester.