Gas vent on side of hull

[wampaku]

I am running all new lines and on the vent lines I was checking the check valves. The top check valve check out fine only let's air in( checked by mouth), the hull check valve I couldn't get to do nothing. So I hooked up the vacuum/ pressure gun and finally got it to pop open. Spray brake cleaner and kept flushing it out. Seems fine with the pump but by mouth I can't get it to blow. Should I replace it? Should it be able to operate by mouth pressure?

 

[Dr Honda]

I would replace it, because brake cleaner will "kraze" plastics.

It should hold a few PSI. probably a little more than your moth can push.

 

[Bills86e]

three valves. Oil tank vent lets air in as oil depletes.
Gas tank bafel line splits allowing breathing, one expell goes out by the rub rail, other is intake and allows air into tank as the gasoline depletes.

All thre operate at 3-5lbs psi.