Fuel tank check valve location question

[CVFD1314]

I'm kinda confused on the location of where I found both the fuel tank air check valve and the tanks pressure relief valve. I'm wrapping up a fuel system over-hall on my '98 GTI w/ single carb, which consists of a lot of new parts. I've ordered both the valves to replace the old ones and was thinking about the location of each one, something didn't seem right with the location.

The lower valve, coming out right under the rub rail on the right side of the ski, is a one way check valve. Letting air IN and not OUT, it's a half white half black valve with 1/4 fittings on each end. The other one comes out higher up inside the hull just under the right side intake grill, about where you right knee would be. That one is the pressure relief valve, which is going to only let air out to keep pressure from building up to high in the tank.

I feel like the two are backwards. The one way check valve (that lets air in) should be higher than at the rub rail, wouldn't water come in to my tank if it's that low? The parts manual doesn't show where it comes out of the ski at, just what hose it's hooked up to. Sooo has anyone ever noticed that on a similar Doo?? I've never had either of the two valves off before and I'm the only owner of the GTI, so I assume they've been that way since I bought it new in 1998. I'm thinking of switching the 2 locations of the valves unless anyone seems to think that's not a good idea for any reason.

 

[Lake Sailor]

CVFD1314, I've got a '97, bet its about the same as yours. My shop manual identifies the valve high in the hull as "Air Inlet", so it would admit air on a low pressure condition in the tank. The one under the bond flange is identified as "Vent" so it should allow the tank to vent overboard on high pressure.

Per my notes from going thru my system couple winters back, the valve at the bond flange is all black, the other one has a yellow cap, yellow end into the hull. Don't remember if they have any arrows or such on 'em.

I think what you're saying is right.

 

[bajaman123]

Definitely possible someone switched them at some point, or are you the original owner? For sure the rub rail check valve is to let pressure OUT, not in.
The rub rail/bond flange one-way valve has an arrow on it, according to the service manual anyway.

 

[CVFD1314]

Lake Sailor, thanks for confirming with your notes about which valve went where. I think I need to start doing that as much work as I have done over the last year.

Bajaman, I'm the only owner, I purchased it brand new in '98 and any work done to it has been by me, so I'm feeling those 2 valves were mixed up from the beginning, that's my best guess.

Thanks for both of your responses, I'm putting those in tomorrow, so I'll put the solid black relief valve through the hull just under the rub rail and the black/white intake valve up higher. Both of the rubber grommets they go through are the same size, so it'll be no problem switching them. Just a mystery how they were backwards...

 

[bajaman123]

Weird stuff can happen. I remember buying a brand new Mazda RX-7 back in 1986. I took it in for service once because I noticed an oil leak on my garage floor. It was only a few month old at the time.
So here comes the service manager over to me saying, "I found the leak, but we don't appreciate this sort of thing here...", and I was like, "Eh?" So he shows me the sending unit that was leaking, and in the bottom of the unit, in what looked to be like JB Weld, was stamped 'Ef you see kay Mazda' (edited for family friendliness here). The service manager was accusing ME of doing this, I told him it wasn't me, I don't think he ever believed me. SOMEONE had to do it at the factory, but this car was built in Hiroshima. What was the story of that sending unit with that obscenity stamped into it? Who knows?

 

[CVFD1314]

strange...

That's hilarious, I've heard of "man made" things coming from the factory like that, just minus the message that was written on yours, Ha! I guess whoever was in charge of putting those check valves in that day mine was made must have been partying the night before.