Prius Bladder System-Tip to Restore Tank Capacity

<div class='quotetop'>QUOTE(ScottY @ Oct 24 2006, 03:47 PM) [snapback]337538[/snapback]</div>

That would be a terrible solution based on my experience with my '06 Prius... it has ALWAYS had problems filling... last week, I had 2 bars showing on the "guess" gauge (good wording, for sure!), and the pump shut off after 2.7 gallons. I was able to, by constantly re-starting the pump after the 3 seconds of filling before it shut off, get the 6 gallons into the tank to fill it up... there is definitely a vapor pressure problem with these bladders... the seal around the nozzle is so tight that the air in the bladder can not escape, and when it does, it usually spews gasoline out of the filler tube. So much for non-pollution!!

 

Every modern car and every current gaspump says to stop filling after the first click. Pumping after that click, unless it was clearly premature, can/does defeat the vapor recovery in all cars. When 99% of folks seem to pay with a credit card at the pump, I cannot understand our obsession with trying to sqeeze in more gas (Prius may be an exception). I would guess that the Prius doesn't have a bigger tank because of space limitations and because a full bigger tank weighs more and will decrease fuel economy for a time...

Doug


<div class='quotetop'>QUOTE(fphinney @ Oct 26 2006, 01:06 AM) [snapback]338454[/snapback]</div>

 

I may be wrong, but isn't the United States the only (or one off the few) countries that have the bladder in the Prius?
Why is no bladder OK for the rest of the world and not us?
And shouldn't we do what the rest of the word does anyway?

 

Today I experienced my second problem filling up my 2005 Prius. The first ocurred a week 2 weeks ago when I filled my tank from half full to full but the gauge stayed on a half full for about a week. A week later I topped off the tank and about 7 miles of driving the gauge showed full. Today, I tried to fill my tank and the nozzle kept tripping as soon as I started pumping. I went to three different stations and finally at the third one I drizzled the gas into the tank to make sure I didn't over fill it because I had no clue to how much gas was actually in the tank. I called my dealership about the problem and the service advisor indicated that there is a sevice bulletin about the issue and that there was another customer in about the same problem. The service bulletin has to do with the replacement of the filler tube. I have to wait until my tank is down to about 1/4 before I can take it in and have it tested.

 

Excuse me, but I paid Toyota for this car. This means I paid Toyota to design it, test it, bring it to market and sell it. Tell me there is another hybrid with this problem and I will stop complaining. But, IMHO, we all paid sufficient money for a car that has a design flaw - can't we please expect Toyota to step up and try to fix it? Why is that too much to ask?

 

Maybe not enough people are having a problem? I've never had a problem filling my tank and I've never run out of gas. I wonder if 3/4 of the problems can be attributed to user error, stupidity, and mechanical issues with improperly maintained pumps and the other 1/4 are legit Prius issues.

 

Have you written to Toyota about it? Have you made sure you are filling the car in 100% compliance with the instructions in the owners hand book?

 

While I haven't yet experienced the dreaded Burp, I understand
that it's occurance is just cause for wondering what the Toyota engineers
were smoking during the design process.

That said, take a look at this technical guidance Toyota provides to its
technicians:

http://www.autoshop101.com/forms/Hybrid13.pdf
(It loads somewhat slowly... )

Where in that labyrinthine mess of piping, subsystems, and sub-subsystems
the problem might lie is well beyond my slowly diminishing capacities...
Good luck on finding a simple work-around.

Me? I make sure I stand off to the side when I fill, and do so very slowly...
all the while suppressing a smug grin.

 

In 8000 miles I only had the burp once. It was proceeded by the unusual all of a sudden clicking off repeatedly. Always since birth this car has gone to same gas station same pump so its not the pump. Now I am trying something new...letting the tank vent for a few minutes before fill. I open the gas cap...leave it open..go inside....buy drink....come out and fill up and now 2 fills later its been fine.Probably has nothing to do with it.

 

Hi:

Does Prius have an EVAP system, with the charcoal canister and all?

I asssumed that the rubber bladder system eliminated all that stuff.

Gary

 

Not entirely sure Prius even has an EVAP system, with charcoal canister and all. The rubber bladder, I think, is supposed to eliminate a lot of that extra plumbing.

Prius tank kinda small, but can drive around quite a bit (400-500 miles) before I feel need to fill up.

Would be nice to go 1000 miles between gas stops, but thats a long time to be hauling around the added weight of another 10 gallons of gas.

Though....If gas keeps going up 10+ cents a gallon per month, there might be some savings from one month to the next if one bought 18 - 20 gallons at a time.

Kind of wonder if I ought to be filling up a couple 55 gallon drums of gas at todays prices to get me through next year.... with interest rates going down, could be better than a bank account! (Yeah, I know... dangerous to store gas at home like that, unless you happen to have a real 'back forty' in which to stash it.)

BTW... Gas 'hoarding' by folks (especially those whose cars get high mpg) could be a problem in future months if oil does appear to be headed towards $200 a barrel range by the end of the year.

Anybody in the South Bay area happen to have an old tanker truck or trailer available? Probably illegal as heck, but maybe worth considering..... A bunch of folks with high mpg cars could probably drain a tanker full of 'cheaper' gas in a year or so before the fuel got too 'stale' to use. Would have to figure a way to make sure some other bloke doesn't try to steal the gas when nobody's around.

Gary...

 

Yes, it's got a full EVAP system, and even uses some features
of it to check that no gas has gotten OUTSIDE the bladder
[but still in the tank]. You can screw up said EVAP system
by force-overfilling. The bladder isn't a floppy balloon, it's
more like a large structured diaphragm so it can't collapse
entirely around the diminishing fuel supply as you drive. It
does help the tank conform to the fuel and adapt to volume
changes, helping eliminate vapor emissions, but for a refueling
event there's still a lot of vapor that has to be captured in
the charcoal canister and then purged later.
.

 

Every auto every sold in the history of automobiles has design flaws. This one is pretty minor considering. I think I can live with it.

... Brad

 

We just ran out of gas in our 4/2008 Prius this week with the gas gauge reading 2 bars and no reserve light. We made it to a gas station on pure electric. Pretty cool as long as you don't overheat any of the electrical powertrain.

 

Take it to a dealer for warranty repair. It isn't supposed to do that.

BTW, there is no separate reserve light: the last warning you get is when the last pip on the gauge starts to flash.

 

Just a thought or question ..i am not technical and may be not understanding this discussion totally.
Wouldn't it be better to then not let your tank go down so low and keep this flexible diaphragm system half full or slightly expanded.
I realize this is not always convenient I also realize some of you are obsessed with this how low can my pips go..without running out of gas..
But I always fill up at around 225 which seems to be about 4pips ( 1/2 tank) and around avg 4.8 gal.

 

So at the end of the day, exactly how do I restore the tank/bladder to the original capacity. I understand that its not the good for the environment and that Toyota engineers are smart people, but I want to actually fill up my car.

 

If you insist on trying to modify this, at least let us know when you jam something in the path of the fuel level sensor and run out of fuel because the float can't reach the bottom. Then when you have to pay for the repairs we can all get a good laugh and say we told you so.

 

i work at a gas station

since owning the prius for 1.5 years, i believe and it is my sincere opinion that the toyota manual that specifies 11.9 gallon capacity does not take into effect of ullage.
and the rreal capacity is actually 89 % liquid gasoline and 11 % vapors, and the best i have ever gotten when the prius was run completely dry was roughly 10.75 and 10.75 of 11.9 is 89 %

when a gas station has its tanks filled up, they are not supposed to go past the 90 % full level so that 10 % is left over for vapors

it is strongly reccomended that you leave 10 % of the tank empty to give gasoline room for the vapor, and room for the gasoline to
condense or expand depending on the surrounding temprature.

that is why a lot of conventional cars will let out a big whoosh sound when you open the gas cap kind of fast, becuase you topped it off
in a way that you did not leave room in the tank for the vapors

 

a gas station tank is fixed, metal or fiberglass or plastic: rigid
thus you have some vapor in there.

the prius tank is a flexible bladder, no vapors inside.
or am i missing something...

your also ignores actual vs useable capacity
just because you have never fit more than 10.75 in there doesnt mean there isn't more inside the tank. an engine can stop due to fuel exhaustion and still have some (unuseable, but real) fuel still in the tanks. any of the other pilots on this board will testify to that