Gas leaking out of charcoal canister?

[84BuickGNYorkPA]

Ok, do I need a new charcoal canister? I have gas leaking out of it, it is hot today and the gas tank is almost full. When I open the gas cap I don't have a vacuum. What should I do? Thanks in advanced... Chuck

 

[Jerryl]

The only way this can happen (IMHO) is of your gas tank is pressurized. Is your check valve in place? There are a few posts on this. Try a search. It may help you narrow it down and post back.

 

[84BuickGNYorkPA]

Check valve? There is one by the canister, not sure if that's the one that you are referring too... I can always replace it..

 

[VadersV6]

In the year and a half that Ive owned my car, Ive heard the gas tank go pshhh after removing the gas cap, like once. Cap is good. Charcoal canister solenoid is good. Solenoid O-ring is good. All hoses are good (that I can see). If Im not getting the pshhh sound, do I have serious problems with my fuel system? Think that some of my crappy mileage could come from simple evaporation since the tank isnt pressure sealed?? Although it does take awhile for gas to evaporate, and I go through 10 gallons every 2 1/2 days so it doesnt really have enough time to evaporate. Ive checked the whole fuel system for leaks, including the gas tank itself, and Ive seen nada.
Even with the solenoid working (I verified it in the lab here at work..it was sticking but I fixed it), could a charcoal canister issue that I cant see, be causing the lack of tank vacuum?
If theres anything I can do to regularly get that pshhh sound, I'll do it. Its always bothered me that it doesnt. What should I look for? The check valves are cheap replacements that were on there when I bought it, and they dont work GREAT, but they do work. It does flow a tiny bit in the wrong direction. But not enough to completely drain the vacuum out of the tank in 5 seconds.

 

[87geeinn]

I removed my charcoal cannister, blocked the line to the vacuum block, and left the return line uncapped so the fuel tank can vent. You don't want/need pressure in the fuel tank.

 

[pacecarta]

Ok, do I need a new charcoal canister? I have gas leaking out of it, it is hot today and the gas tank is almost full. When I open the gas cap I don't have a vacuum. What should I do? Thanks in advanced... Chuck

in pa you pump yourself ,
dont top it off when you fill it ,

vent is on the top of the tank and only way to get raw feul is filling tank too much and then having car sit at an angle so as to have the fuel level covering the vent. add some pressure from fuel sloshing or warm day and fuel will get pushed up the vent line and out the cannister .

 

[84BuickGNYorkPA]

Ok thanks for the reply's. It only happens when, the tank is full or near full. I always stop when the pump clicks off the first time, and the first time it happened was last fall after I put the high output fuel pump in the tank. Maybe after reading these responses the bigger fuel pump is contributing to the return line pressure/volume, plus the heat factor... expansion.... it's starting to make sense. So for now don't worry about it, just try to park it with the tank down grade from the motor. If this becomes a regular problem, I will have to do something. Unfortantly I don't put gas in it but three times a month maybe.... Thanks for the reply's again, they are greatly appreciated.

Chuck