Fuel System Leak Test
Test Conditions
- "Fuel System, Checking for Leaks" performed. Refer to FUEL SYSTEM, CHECKING FOR LEAKS .
- The :KLI9210 must be connected to the vehicle with the :KLI9210/57 .
-- Connect the :KLI9210 to the vehicle battery.
-- Remove the right rear wheel housing liner.
-- Clamp off the hose between the Leak Detection Pump - V144- -item 8- OVERVIEW - EVAP SYSTEM, FUNCTION List Item:Leak Detection Pump -V144- and air filter -arrow- -item 7- OVERVIEW - EVAP SYSTEM, FUNCTION List Item:Air Filter.
-- Set valve -D- to "Test".
-- Observe the pressure gauge -C- and flow meter -E-. If the flow quantity decreases and pressure increases to 10 in. H2O (25 mbar), 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 -V144-.
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 fuel system with smoke by setting valve -D- to "Test".
-- 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 fuel system lines and hoses for escaping smoke. Also check fuel tank sealing 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 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 fuel pump and fuel filter flange, the assembly openings in the vehicle interior must be opened.
-- Replace leaking hoses or components.
After completing the work, perform the "Check tank ventilation system for leaks" Guided function using Vehicle Diagnostic Tester.