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Product Information
Product Information

Fuel Expansion Tank – US Cars

Restore the correct operation of your classic Porsche fuel system with this Fuel Expansion Tank. Specifically designed for USA specification Porsche 911 models built between 1970 and 1973, this high-quality replacement is manufactured to OE specifications, ensuring excellent fitment, durability and reliable fuel vapour management.

Fits:
  • Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)

Diagram ref no 3


The fuel expansion tank is an integral part of the evaporative emissions and fuel venting system. It allows fuel to safely expand as temperatures rise while separating liquid fuel from vapours before they are returned through the venting system. This helps prevent fuel overflow, reduces fuel odours and maintains safe pressure within the fuel tank.

Over time, the original expansion tank can become brittle, crack or suffer internal deterioration due to prolonged exposure to fuel, heat and age. Replacing a worn or damaged tank restores safe operation and helps preserve the originality of your Porsche 911.

What Does the Fuel Expansion Tank Do?

The fuel expansion tank is designed to safely manage expanding fuel and fuel vapours generated inside the fuel tank.

Its functions include:

  • Allowing fuel to expand safely during temperature changes.
  • Separating liquid fuel from fuel vapours.
  • Preventing fuel overflow.
  • Helping maintain correct fuel tank pressure.
  • Supporting the vehicle's evaporative emissions system.
  • Reducing fuel vapour loss.
  • Protecting surrounding components from fuel contamination.

A properly functioning expansion tank contributes to both vehicle safety and efficient fuel system operation.

Why Replace the Fuel Expansion Tank?

After decades of service, original plastic expansion tanks often deteriorate due to constant exposure to fuel vapours, heat cycles and ageing.

Replacement is recommended if the tank has:

  • Cracks or splits.
  • Fuel leaks.
  • Brittle plastic.
  • Fuel odours.
  • Damaged hose connections.
  • UV or age-related deterioration.
  • Internal contamination.
  • Signs of previous repairs.

Replacing the tank helps eliminate common fuel system issues while restoring reliable vapour management.

Symptoms of a Failing Fuel Expansion Tank

A deteriorating expansion tank may cause:

  • Strong petrol smells around the vehicle.
  • Fuel leaks in the front luggage compartment.
  • Dampness around vent hoses.
  • Fuel overflow after refuelling.
  • Cracked or discoloured plastic.
  • Poor fuel tank venting.
  • Perished hose connections.
  • Increased fuel vapour emissions.

If any of these symptoms are present, the expansion tank and associated vent hoses should be inspected and replaced where necessary.

Benefits

Installing this OE Match Fuel Expansion Tank provides:

  • Restores correct fuel vapour management.
  • Helps eliminate petrol odours.
  • Reduces the risk of fuel leaks.
  • Maintains safe fuel tank pressure.
  • Protects surrounding components.
  • Restores factory appearance.
  • Excellent fit and finish.
  • Ideal for concours restorations and routine servicing.

Installation Recommendations

Professional installation is recommended when servicing the fuel venting system.

While replacing the expansion tank, it is advisable to inspect or replace:

  • Fuel vent hoses.
  • Rubber connectors.
  • Hose clips.
  • Fuel filler neck hoses.
  • Fuel tank seals.
  • Fuel sender gasket.
  • Vapour recovery lines.
  • Charcoal canister hoses (USA models).
  • Fuel tank breather components.

Replacing ageing rubber components at the same time helps ensure a leak-free and reliable fuel system.



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