At 17000 miles had the "pop off" replaced on the fuel tank cause it would only take 4-5 gallons before shutting off the gas pump. Knew it should take 6-7 based on the mileage. Now at 42000 it's doing the same thing, can't fill the tank unless you pump at a dribble. The gas guage doesn't seem to be working either. Anyone else have this problem ??
Not for me either, and I'm at 55,000 miles. I have run into a couple of bad filler nozzles, but that's not quite the same thing. Tom
The gas tank has a valve to releive the pressure that builds up in the tank as you fill it. The tank is metal with a bladder inside that holds the gas. The valve lets the air out of the metal tank as the bladdder fills. If the presure is not releived it appers the tank is full because of the back pressure. I went 350 miles and got 4 gallons in the tank before the pump shut off. I'd like the 90 miles to the gallon but....
intersting. are you going back to the dealer for another one? maybe the back pressure is affecting the gauge sensor as well?
The problem is well known and commonly referred to as the "gas bladder problem". This is the first time I heard of the explanation being a bad valve. Usually people say it's the bladder got more stiff sometimes and more flexible some other time. I like the valve explanation much better though.
Hi I'm kinda new to this site but, I just had this problem today! I'm relieved and troubled at the same time that others have experienced this issue with the bladder gas tank. My trouble was as soon as I started to fill from empty (9.5gls). I had to squeeze very carefuly for the entire 9.5gls. No other problems as a result of this condition, so I'm hoping that it was the pump nozle rather than the car. I have never seen a bladder filled gas tank before so this is wierd to me, not sure why its used and are they being used in other vehicles?
I'm having the problem in warm weather so I don't think it is the bladder's condition. It seemed to start out slowly both times. The 2nd time I was more aware and noticed it seemed to start with just the last gallon or two of gas on fillup. Now I can't fill the tank more than 1/2, I would guess before it requires the gurgle method to fill the tank. Now my concern is I have 45000 on the car and it's out of warranty. I'm ready for the "discussion" since this is the 2nd time for the same problem . Can't get the car in till Oct 8 due to vacation plans.
If the burping problem is in the pump, the most likely cause would be some blockage of the tube that returns the displaced air in the Prius' tank to the underground tank: A second possible defect in the pump handle is a small plastic valve that lifts as the displaced air escapes the gas tank. When the air stops flowing, the valve drops and signals the pump motor to stop. If the valve is worn it can signal prematurely. The only "fix" in these cases is to use a different pump. There is some variation in the size of the gas bladdder: There is a Service Bulletin on the Gen II fuel system: View attachment T-SB-0163-08.pdf For a complete run down on the Gen II fuel and evap system, go here. There have been many, many threads about this issue. Use the Search Tool with "burp" to find them. Hope this helps.
The bladder was used to minimize the exposed free surface of the gas, thereby reducing evaporation and resulting emissions. Fuel bladders have been used for a long time, but not commonly in passenger cars. Typically they were used to reduce the risk of fire in crashes and to make self-sealing fuel tanks for military aircraft. The new 2010 Prius no longer uses a bladder. Tom
even though you are out of warranty, because they already replaced it once, i would think they will take care of the problem no charge. all the best, let us know!
Ok..... I filled the tank twice since this post with out problems. I'm thinking that the bladder tank may cause some already sensitive pumps to react worst than without bladder. This I conclude from useing the same pumps for yrs with a Focus and somtimes felt that some pumps were more sensitve than others cause they would shut off prematurely.
