Fuel System, Checking For Leaks: Procedure

-- Remove the right rear wheel.

-- Remove the right rear wheel housing liner. Refer to WHEEL HOUSING LINER .

-- Remove the breather line -2-. Disconnect the connector couplings. Refer to CONNECTOR COUPLINGS .

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Evaporative Emissions Tester :KLI9210 Preparation: 

-- Check the :KLI9210  to make sure there is enough fluid in the smoke generator.

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

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-- 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. H2O).

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

• The pressure must now be maintained for a minimum of 2 minutes.

If the pressure is not maintained, check the tester.

FUEL SYSTEM, CHECKING FOR LEAKS 

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-- Connect the :KLI9210/55-1  to the vent lines -A- "white markings" as illustrated. Refer to Color Coding  => Ventilation  .

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

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-- Connect the Vehicle Diagnostic Tester to the vehicle.

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The procedure changed when the electrical Leak Detection Pump -V144- was introduced.

-- Switch the ignition on.

-- Select the Guided Functions  operating mode on the Vehicle Diagnostic Tester.

-- Select the Check Tank Ventilation System For Leaks  .

-- Start the test.

-- Watch the pressure gauge on the Evaporative Emissions Tester :KLI9210  .

• The Leak Detection Pump -V144- must pump the fuel system pressure up to at least 25 mbar (25.40 cm. H2O).

The Minimum Pressure Is Not Reached And The Pressure Reached Decreases Immediately: 

-- Clamp off the hose to the EVAP Canister Purge Regulator Valve 1 -N80- with a hose clamp -arrow-.

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-- Repeat the test. If the minimum pressure is now reached: Replace EVAP Canister Purge Regulator Valve 1 -N80-.

The Minimum Pressure Is Not Reached Again Or The Pressure Reached Decreases Immediately: 

-- There is a leak in the fuel system: Perform the test "Check for Leak In Fuel System. Refer to Fuel System Leak Detection  below.

FUEL SYSTEM LEAK DETECTION 

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

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-- Connect the :KLI9210  to the vehicle battery.

-- Remove the right rear wheel housing liner. Refer to WHEEL HOUSING LINER .

-- Remove the connecting hose from the air filter to the Leak Detection Pump -V144- on the Leak Detection Pump -V144-. Refer to -item  ) Connecting Pipe-.

-- Seal the opening on the Leak Detection Pump -V144- with suitable plugs from the :VAS6122  . Refer to -item  ) Leak Detection Pump -V144--.

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

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-- Watch the pressure gauge -C- and the 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 the valve -D- to "Hold".

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

If The Pressure Drops Or If No Pressure Develops, Then Locate The Leak As Follows: 

-- Fill the fuel system with smoke. Set the valve -D- to "Test" again.

-- While 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 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 assembly opening in the vehicle interior -1- to check the flange on the fuel pump and fuel filter.

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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.