55 Wasp Gas Tank Venting

[supercub 40]

I removed my gas tank for restoring, and I dont see any vent system on the tank or body. There are ports for the sender, pickup line and filler neck. The filler neck joins to the tank with a rubber tube about 4" long. That hose and its clamps are newer replacements. The gas cap looks original with the chrome H design, no vent holes on it. Everything looks original on this car, 42,000 miles on it.

Does anyone know how the Wasp tank is vented?

[auburnseeker 4,516]

If you don't see a separate vent,  i would assume it's vented through the gas cap.  Very common on alot of old cars. 

[supercub 40]

I looked at the cap and there isnt a venting feature on it.

 

[paulrhd29nz 79]

It may not have an air tight seal on the cap. Try with very low presser to blow air in the the fuel pick up with the cap on. Release the cap after a few seconds and if air tight, the cap will pop off. It shouldn’t be air tight is my guess. 

[Marty Roth 2,567]

Your gas cap may be a very nice non-original.

If the old tank didn’t have a separate vent then the cap should have a vent.

just because it has the chrome “H” doesn’t mean it is for the correct year and model 

Edited January 10 by Marty Roth (see edit history)

[supercub 40]

I will do the air test tonight. The cap looks to be made pre-China. The workmanship and hardware, as well as the dried up seal, appear 50's. There could have been a different cap on it originally. The other model Hudson tanks that Ive seen online had hose nipples on the tank top for a vent line. 

[supercub 40]

The cap as a spring loaded seal plate that retracts to an open area for venting when screwed onto the filler.

[paulrhd29nz 79]

So there you go. You've discovered your tank vent. 👍