small tube off mechanical fuel pump

[larrys]

Building a 14A with a 390 Lycoming
Would anyone know where the small tube off the mechanical fuel pump goes? Would you have pictures or where I can find it in the plans.
Thanks! Larry

[Tom023]

Larry,

If you are referring to the white translucent tube, it is there as an overflow and indicator if the diaphragm develops a leak. You will see blue fuel stains in it if your pump is leaking. It just goes down in the tunnel behind the nose gear behind the brace that runs across the tunnel opening. Mine exits pretty close to the breather tube opening.

[larrys]

Originally Posted by Tom023

Larry,

If you are referring to the white translucent tube, it is there as an overflow and indicator if the diaphragm develops a leak. You will see blue fuel stains in it if your pump is leaking. It just goes down in the tunnel behind the nose gear behind the brace that runs across the tunnel opening. Mine exits pretty close to the breather tube opening.

Thanks! I could not find it on the plan, but now I know
Larry

[pazmanyflyer]

Originally Posted by larrys

Building a 14A with a 390 Lycoming
Would anyone know where the small tube off the mechanical fuel pump goes? Would you have pictures or where I can find it in the plans.
Thanks! Larry

See section 43: Engine Installation
Pages 43-05, 43-06

Also section 49: Fuel & Oil System
Page 49-18 for attachment with picture.
Step 5 for taildragger or step 6 for -A model.

[dlloyd3]

It drains the very small space between the 2 diaphragms. If either the gasoline side diaphragm or the oil side diaphragm leaks, you will get either gasoline or oil dripping from the drain. Pump keeps pumping.