Now that I have your attention...

Every time I open my gas tank I have either positive or negative pressure (sucking or blowing). Is this normal? Is the tank vented? Perhaps through the cap?

 

Hmmm, it should be vented through the overflow hose that goes out the bottom (1 of 3 hoses). Never heard that on mine unless your hose is plugged up.

 

yea mang...check your hoses...pull the tank and check to make sure it's not crimped or blocked...why? because in due time, the pressure will cause the tank to bulge out or dent!

 

EPA doesn't allow direct tank venting. The overflow serves the area around the filler neck. Is perfectly normal to have vacuum/pressure in the tank. You guys have to have heard this from your cars too ?

The tank is "vented" but only after a certain psi, like a radiator cap.

 

hey fats...yes, the overflow is above the filler neck line and comes out...so not truly 'open' but what he's describing is a bit too much...it should be so much to be totally noticeable as he describes.

 

I don't know how much is too much to him or you, but w/where he is from, BIG temp swings can cause what he seems to be describing. 60 dergee temp swings and triple dig highs are both causes for a lil tank vac/pressure. Most e/thing newer than about 90 have had what i would consider a sealed tank. There is alway a vent, but some pressure or vacuum is normal. He also stated that it changes from pres/vac which makes me think its normal. I hear it all the time from customers. What i meant about the overflow tube is that its "outside " of the tank itself. Drains overflow, is not a vent.

 

Thanks for the feedback!

Actually the pressure HAS caused the tank to dent. I spoke in a previous post that I had dents that had begun to leak fuel and I think the reason is from this pressure.

I have been told, by a Honda dealer service rep. that the gas tank vents through the cap and so I have ordered a new one. I hope that this fixes the problem. The price for a new honda cap is around $150. [:@]

 

WOW !! Takes a LOT of pressure to dent the tank ! I had not read that post ! Yea a new cap sounds like a good idea !! My 02 f4i would vent pres/vac when opened, but no denting. Maybe the cap was going bad on it too !?

 

maybe he has your old F4i FATHEAD? hahahah...

i guess it vents through the cap, but not out from the to of the cap, but rather, downwards through the overflow eh?

 

Maybe !! I'm gonna side step outta this one now.... since my advice was WAY off !! [sm=oopssign.gif]