Gas Tank Pressure Relief Hose/Check Valve

[blackbyrd]

It's another late night working on the car, so indulge me.. I removed the charcoal canister and was going to vent the pressure relief hose from the fuel tank, to the ground behind my engine bay. I noticed there's a little plastic check valve in line with the hose. I assume to allow excess pressure to be relieved from the fuel tank gases, and not to allow air to travel back into that pipe to the fuel tank...
Does that sound right?
Because I took off the check valve and blew into it in the direction exhaust gases would be traveling out of the tank, and It shut. But I could blow into it the other way... So as it was it wouldn't allow fuel fumes to escape, but allow air and what not from the charcoal canister or whatever it went to, to travel through it and into the gas tank...
Make any sense?
I figured okay some idiot just had it turned around backwards, but I look at the arrows on it and the arrows are pointing the direction it was hooked up. IE, the arrow points ----> but you can't blow any air in that way..
WTF?
Am I just lunching? Does it only open under a certain amount of pressure? Is this why everytime I would fill up my gas tank the nozzle would shut off 20 times?

Maybe someone could enlightened me.. I was just going to vent the tube, figured I'd keep the check valve if it serves a valuable purpose. Maybe put a filter on the end of the hose? Haven't decided.

Thanks!!

 

[blackbyrd]

So I was doing some more thinking about my post, and searching around for answers(which I couldn't find). But I came across a couple people saying if you have the wrong gas cap on your tank it can cause some serious problems..
Didn't really think of it before, but I have a "Honda" gas cap(came with it when I bought the car years ago). I assumed it was put on there with some knowledge that it was the same as the DSM.. Is it? I couldn't really find any info on that either.
Is that whats causing all the pressure in my tank and always being a PITA to fill up?

I know, it's a slightly related question, but I didn't really want to start a new thread for it.

Thanks again!
Happy Turkey Day!

 

[Th3ory]

I have to raise this old thread, I took my charcoal canister off, and found this plastic valve on my fuel tank vent line, however mine is old, dryed and cracked. Has anyone replaced this with a parts store check valve? Or is it something special? I have a picture of it, if that helps.

I am going to try and finish my custom fuel line this weekend, but would really like to get a new "check valve" or "pressure valve"-I don't know what this valve is? I don't live to close to any dealerships to order this stock "whatever valve". Anyone have experience with the gas tank vent "valve"?

Here is the valve, anyone know if I can replace this with a generic one way check valve, something like how a pcv valve flows? This is what I have read while searching information on this valve, just trying to make sure its not something else. It is cracked and I would like to get a properly functioning replacement, maybe I will run it to Shucks and see if they get anything with the OEM part number.

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[krygods]

I'm not having any luck viewing the pictures you posted.

 

[Th3ory]

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[krygods]

Part number is right on the side of the valve can read it in the picture above.

MB925886

http://www.mitsubishidirectparts.com/oe-mitsubishi/mb925886

 

[Th3ory]

Hope that works.

Part number is right on the side of the valve can read it in the picture above.

MB925886

http://www.mitsubishidirectparts.com/oe-mitsubishi/mb925886

Yeah, I can order it, however I was wondering if I can use a generic check valve. Over the counter from any auto parts store? If not, I will go threw that website, that's not a bad price. Would like to use a generic if that's all the valve is though ( a simple one way valve?). Thanks!

After a bit more reading, it appears as though it is set to vent at a certain PSI. I better stick to oem... thanks

 

[krygods]

I see, I'd also do the same.