Seat Leon >> Natural gas system: Visual inspection of the natural gas tank for corrosion and implementation of a leakage test

SEAT Leon Service and Repair Manual / Maintenance / Description of work / Natural gas system: Visual inspection of the natural gas tank for corrosion and implementation of a leakage test

Special tools and workshop equipment required

  • Gas leak detector for natural gas vehicles - VAS 6227-

  • Mirror
  • Lamp - VAS 6901-

CAUTION

For reasons of safety, service and maintenance of the natural gas system may only be meticulously carried out by specially trained personnel.

Natural gas is highly inflammable and, in combination with air, creates a combustible mixture.

There must be no open flame or source of ignition near the natural gas system.

Inhaling natural gas can lead to light-headedness and lung damage. There is a risk of suffocation due to lack of oxygen with higher concentrations.

Natural gas is NOT odourless because a gas having a strong odour is added.

Test requirements:

  • All parts of the natural gas system to be checked must be reached easily.
  • The exhaust gas warning lamp in the dash panel insert must not light up and there must be no entries concerning natural gas in the event memory of the engine control unit.
  • Workplace without draught.

NOTICE Every draught of air above 1.8 km/h (slight gust of wind) will result in falsification of the measuring result. Therefore, it is essential to work in a draught-free environment.

When working on the natural gas system always ensure for tidiness and cleanliness!

Visual check:

  • Remove the air filter housing.
  • Remove underbody trim.
  • Check natural gas system for corrosion and security.
  • With the aid of a mirror, carry out visual check of complete natural gas tank.
CAUTION

If corrosion is found on the natural gas tanks during a visual check, the respective component must be renewed for reasons of safety.

Corroded natural gas tanks can burst under pressure and cause serious injuries.

NOTICE Exchanging is a repair measure!

Leakage test:

  • Switch on ignition and start engine to set the pressure ratios in the gas system to the operating mode. For the leakage test, the engine can be switched off.
WARNING
  • Pressurised natural gas may escape from natural gas tanks.
  • Natural gas is highly inflammable and, in combination with air, creates a combustible mixture.
  • Close fuel tank shut-off valves manually.
  • Using gas leak detector for natural gas vehicles - VAS 6227- , check only indicated test locations -arrows- for leaks. It is absolutely necessary to check all threaded connections of the gas system.
  • The probe must have a clearance of maximum 5 mm to the sector/component being checked! Where the clearance is more than 5 mm measurement is no longer possible.

Maintenance

NOTICE The gas leak detector can only be used to find out whether there is any gas in the surrounding air.

Any other result than a green LED for O. K. is not permitted on the gas leak detector. As soon as a yellow or red LED lights up, a leak detection spray must be used to obtain clear proof of whether gas is really escaping from the vehicle's system or not.

When leak detection spray is being used, it must be ensured that no bubbles come out of the sprayed area within a testing time of 3 minutes. If leaks occur, they must be repaired and the gas system test must then be repeated.

Checking positions:

Maintenance

 

Maintenance

  • Natural gas filler neck -arrow-.
  • Distribution piece -arrows- on the vehicle underbody.
  • Tank shut-off valves for natural gas tanks 1 and 2 with all connections, threaded connections and mechanical shut-off valves -arrows-.

Maintenance

 

Maintenance

 

Maintenance

  • Check electromechanical high-pressure regulator for gas mode with all connections and threaded connections -arrows-. Check condition of low-pressure hose -1-.
  • Gas rail with gas injectors -1-, gas rail sensor -2- and connection for low-pressure line -3-.
  • Install the air filter housing .
  • Install underbody trim .

Maintenance

Natural gas tank: Renew

CAUTION

Service and maintenance on the high pressure part of natural gas system must only be performed by specially trained personnel.

Natural gas is highly inflammable and, in combination with air, creates a combustible mixture.

There must be no open flame or source of ignition near the natural gas system.

Inhaling natural gas can lead to light-headedness and lung damage. There is a risk of suffocation due to lack of oxygen with higher concentrations.

Natural gas is NOT odourless because a gas having a strong odour is added.
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