Fuel Tank and EVAP System, Checking For Leaks

Fuel Tank And EVAP System, Checking For Leaks


NOTE: In the following, individual questionable points will be considered that could be leaks in the fuel tank and tank ventilation system. After eliminating a possible leak, it is effective to then perform a tank leak diagnosis to determine whether the leak was successfully sealed.


- Switch OFF ignition.
- Check if filler cap was completely closed for the test.
- Check if filler cap seal is damaged or crimped, replace if necessary.
- Check if the gaskets under the cover flanges are OK and if the union nut on the fuel tank cover flange is correctly tightened.
- Check hose connections for tightness and integrity repair or replace as necessary.
- Remove luggage compartment trim.
- Remove connector flange cover under luggage compartment trim.


NOTE:
Observe the cover flange installation instructions.


- Visually inspect all fuel tank system line and hose connections and replace any leaking lines, for example:

- Line from EVAP canister to EVAP canister purge regulator valve in engine compartment.
- Lines from EVAP canister to the LDP (under left wheel house liner).
- Line from the fuel tank to the EVAP canister (under the cover for the EVAP canister).
- Lines of the tank ventilation system (under right wheel house liner).
- Fuel lines to the engine.


NOTE: Locate leaks at lines and components of the tank system by using a non-combustible, environmentally friendly, leak detector spray. Perform several leak diagnostics in a row to build up the system pressure. Bubbles will form at points of leakage.


- Visually inspect the fuel supply system components:
- Fuel tank
- EVAP canister
- LDP
- EVAP canister purge regulator valve -N80


NOTE: At times, the above components cannot be effectively leak tested using a leak detection spray, either because of component location or function. In such cases, clamp off the lines to the component involved and perform a leak check. If the leak is no longer displayed, the clamped off component is faulty. If the LDP is clamped off and there is still a leak displayed, the LDP is faulty.


- Check EVAP canister purge regulator valve -N80.