Fuel System Leak Test

Fuel System Leak Test

Special tools, testers and auxiliary items required

• Hose clamps up to 25 mm dia. (3094)

• Fuel system tester (smoke tester) (KLI 9210)

• Adapter hose (KLI 9210/55-1)

Test Conditions

• The checking fuel system for leaks test was performed. Refer to --> [ Fuel System, Checking for Leaks ] .

• Connect the (KLI 9210) and the (KLI 9210/55-1) to the vent line.





Test Sequence

- Connect the (KLI 9210) to the vehicle's battery.

- Remove the right rear wheel.

- Remove the right rear wheel housing liner.

- Clamp the connecting hose between the Leak Detection pump (LDP) and the air filter using the (3094) - arrow -.





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





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

• Depending on the level in the fuel tank, this procedure may take up to 3 minutes.

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

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

If the pressure no longer drops now:

- Replace the LDP. Refer to --> [ 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 the valve - D - to "Test".

- While 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 fuel system lines and hoses for escaping smoke. Also check the fuel fill cap.

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

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

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

• In order to check the fuel delivery unit flange, the cover under the rear seat bench must be opened.

- Replace any leaking hoses or components.

- After completing the work, perform the Guided Functions, Check tank ventilation system for leaks using the vehicle diagnosis, testing and information system (VAS 5051B).