Improved Fuel Vent Lines

Stops fuel waste!

• Stops asphalt damage.
• Stops environmental damage.
• Fly with full tanks.
• Extends useful range.
• Pays for itself quickly at $5 per gallon.
• Adds value to your airplane.
• FAA-PMA direct replacement, no STC or 337 form needed.

The fuel vent line on most Cessna single engine aircraft attaches to a check valve inside the tank to prevent fuel from flowing out of the vent line, but this valve has a weep hole that allows some fuel to pass to prevent pressurization of the fuel tanks. Unfortunately, this weep hole is much lower than the fuel level of a full tank. Fuel will continuously leak out of the vent line until the fuel level is below the weep hole. With the original vent line, you cannot fill the tanks without wasting a lot of fuel.

The Cessna heritage aircraft also have a tank interconnect vent line that allows fuel from both tanks to leak out of the vent. When parked on an unlevel surface, the fuel loss from these aircraft may be many gallons.

McFarlane has solved this problem with a redesigned vent line featuring a unique hump that rises above the top of the tank. Some fuel can still escape through the weep hole and out the vent to prevent pressurization of the fuel tanks. However, fuel will stop leaking once the pressure is relieved, and the tanks will remain full.

Installation Tip:
Access to loosen to tighten the vent line in most of the Cessna aircraft is very tight because the tube flare nut ("B" nuts) sits partway in the wing rib. However, with the right wrench, you can normally loosen the nut from the under-wing inspection holes without removing the top tank access skin. The fitting in the tank has indexing flats and will normally not rotate while the tube flare nut is being loosened and re-tightened for the new line. Use caution in starting the nut as the tank fitting is a welded assembly with soft aluminium. Be sure not to cross-thread or over tighten the nut as you can easily strip the threads on this fitting.