Fuel tank bladder collaps

You could put 10 or 11 gallons before??? Im shocked. The most ever put in was 8.75 gallons. Tried different pumps and no fuel bars flashing.

 

You could try the fuel gauge calibration to help eliminate the gauge as the problem.
Fuel Gauge Calibration Instructions | PriusChat

 

Try the recalibration first. If the bladder holder was crushed, it would have been replaced, repaired when the rear end damage was taken care of. Yesterday with two pips showing, I was able to stuff 7 gal in! 47.4 MPG!
Waiting a couple of years to bring this to the Insurance Company's attention, not so good!

 

So it sounds like the fuel tank has been inspected and there is no issue. Assuming no ill will that is not them not standing up for you but rather them not wanting to commit insurance fraud.

If this has been going on for 2 years you need to step back a bit. The folks at both the insurance company and the dealer have dealt with this a number of times and the hard and honest truth is that they have stopped listening to you. They feel that they are correct in their decision. If you firmly believe this you need to do one of two things -bring the car to another dealer or mechanic or you can have the tank pulled, inspected and if needed replaced at your expense. If the tank is damaged and it can be tied back to the accident you can then look to get reimbursed.

I too think that you might be focusing on the wrong item. There is more than just the fuel tank involved in the problem that you describe - specifically the fuel gauge. Gauges on all cars are inaccurate, and the Prius is no exception. When my 2009 shows 1 pip left I can fill up with about 7 gallons. I have tried resetting it to no avail. When the gauge reads empty you really do not know how much gas is actually in the tank - it could be a few tenths of a gallon or a few gallons. The cheap and easy way to tell is to drive the car until you would normally fill the tank. Then siphon the remaining gas - I hear it is tricky to do but not impossible.

 

Fuel pump, and if u drive it on the battery u could run it too low then when u do put gas in it the car will not start.

 

I did not suggest this as I worried that the poster might run the car to empty with a few gallons of gas stored in a can in the trunk area, something that is not all that safe in the open interior of the Prius. At least here in PA it is not even legal to do so. But the potential damage to the traction battery is another good reason - even if you notice the gas engine stopping, but could be in a spot where stopping is not a terribly attractive option.

 

Hoo Boy! I don't like the sound of this.

+1 on doing a fuel gauge level recalibration. It would be the simplest possible fix.

As posters have noted, the Gen II Fuel and Evap system is far more complex than can be anticipated.
A first step in trying to appreciate the situation -- actual understanding is a wholly different matter --
would be to review the system layout, etc. To this end I have created a thread in the FIles forum that
has a downloadable PDF attached that has the Fuel and Evap system details. Look through the PDF,
you'll be surprised, unpleasantly so I suspect. As a minimum it will suggest why most dealers want
nothing to do with troubleshooting Gen II Fuel and Evap System problems.

Gen II Fuel and Evap System PDF | PriusChat

I won't even hazard a guess as to what failures in the myriad of parts might be the real problem… I am
reminded that an inadvertent over fill can cause one of the carbon canisters in the system vents to get
fouled and screw up subsequent fuel level readings.

Getting a handle on what ails you car is doubly complicated by the interaction of the Fuel and Evap
System with the infamous 'guess gauge.' IIRC, should you run the fuel tank empty, the guess gauge
does not recognize anything less than 3 gal. of fuel added to the tank.

The Gen II fuel tank is a closed system with the accursed bladder, fuel pump, fuel gauge sender, fuel
filter and other bits enclosed in a welded steel 'tank.' While in the past there has been some discussion
of opening up the steel tank, I am not aware that anyone has successfully done so. I am afraid that if the
fuel gauge level recalibration is unsuccessful, the highest probability for a fix may be replacement of the
steel fuel tank and all the bits and pieces that it encloses.

Along these lines, I would contact a reputable Prius salvage parts supplier. Plug In Hybrid Electric Vehicle PHEV has
demonstrated a solid history of helpfulness, technical competance, trustworthiness, rapid service, and low cost.

 

Doing so would be the equivalent of the cartoon!
Gen II's should NEVER be driven dry, nor overfilled. If overfilled you destroy the vapor recovery system, ouch! Running dry requires at least 3+ gal be put into the tank!
How many miles do you get to a tank in the summer? I do 47/48. I have a hill to contend with!
Another thought, since the tank is a sealed unit, there is a bleeder valve between the rubber whatever bladder and the steel housing. as you fill, you have to displace the air in the steel tank, or the TANK WILL NOT FILL properly.
Read the PDF that Rokeby posted, as you will see it's not just a tank, it's a system.

 

Living in the UK the gen2 Prius over here does not have the bladder. The gen3 Prius does not have the bladder on either side of the pond. So would it be possible or even legal to fit a gen3 tank in the gen2 thus overcoming all the bladder problems.

John (Britprius)

 

It sounds logical John, but I would bet there are technical differences between the two systems. I haven't seen the Toyota specs or Training Info for the Gen III, but I have seen publications for the Gen II bladder system. I would guess that the systems would be different in many aspects and probably not interchangeable.

Hopefully Patrick Wong will chime in on this, as it is something worthwhile to consider if it is physically possible. The next question would be the cost's involved. Chances are it would be a considerable amount of modification and therefore a possible large sum of money involved for the retrofit.

Ron

 

Obviously the logical way would be to use the gen2 UK/EU tank. I realise this would still mean some ECU spoofing for the fuel sniffer system, but how does this work with the gen3 with no bladder? And of course the gen2 non bladder tanks are not available to you making the gen3 tank the obvious choice. Is this just the same system as used in any other car or is it the same as the gen2 UK/EU system?

I do know in certain states it would be illegal but not sure about the rest. I often think when filling my own car, and having no problems whatsoever being able to fill the tank reliably and not having burp problems.

One blow back of fuel on one car in the US, must introduce into the atmosphere more pollution than the rest of the vehicles save.

In the UK our fuel filling arrangement is different to the US. It is illegal to have a device on the fuel pump filler to allow it to operate automatically, you are only allowed to fill manually. Meaning you cannot let go of the pump filler handle when fueling the car.

John (Britprius)

 

A lot of people claim bladder problems but what is the reality? If you can only put 7-8.5 gal's in the car, that means you're only running out 7-8.5 gal's. This has happened to me before but what I do is just assume I have at least 10 gal's to burn and calculate distance for 40mpg's or 400 miles. Then, no matter what the gauge says, I drive 400 miles. I have never run out of gas, nor have I ever put more than 9.5 gal's in the car. I should try 450 miles one of these times and see what happens.

As for running the car out of gas causing problems, I can't imagine how running the car out of gas one time would cause a problem. I'm sure you would get the trio of lights but, as far as burning out the fuel pump, I call bullhockey!!!. A lot of people like to treat these cars gently (which I don't condemn at all). I might even say they are, overprecautious but my experience tells me that these cars are really pretty bullet proof.

I'm certain to receive a lot of pushback for saying this but really, these cars are very reliable. The worst thing you can probably do to them is reverse polarity when jumping the car. Other than that, they are very robust.

 

Way back when I took drivers ed I was taught that running out of gas could damage the fuel pump either by causing it to sunk in gunk at the bottom of the tank and air or since many pumps sit in the tank they are kept cool by the gas. I always got the feeling that this was more of a disclaimer - something that could happen but was not at all a certainty.

Most cars will sputter and surge before they run completely out of gas. With the Prius you may not even realize you are out of gas until you run the hybrid battery to empty.

The bigger issue is do you really want to run your car all the way to empty? You do not know exactly where and when it would happen - on a side street near a gas station - not a big deal. In the center lane on the highway - could be a big problem.

 

I know that the above and my reply could be considered to be slightly off topic to the OP post, however I feel it is very valid. With the guess gage being the way it is and the bladder thrown in to compound things, running out of gas in a Prius or any car as far as that goes can be a bad thing in certain circumstances.

Recently my good friend made this statement to me concerning gas tanks and volume thereof. He said "It is much easier to run on the top half than the bottom half".

Ron

 

Yes we have the same reported by other members before. It's 11.2 gal, if I remember right.

 

Actually, the Gen II is rated at 11.9 but that is only a rating. It seems that many have found different maximum amounts. Of course, not everyone is filling their tanks the same way with the same nozzles at the same pump.

Sorry to get off topic from the OP post, I was replying strictly to ahmeow's posting of 11.2 gal

Ron