confirmed overfill damage

auto shutoffs work by back air pressure. in a normal fill, the nozzle forms an airtight seal, air pressure is flowing back into the nozzle via the little hole. (the big hole is where the gas comes out). while expanding the tank, the back air flow is light enough to not actuate the shut off valve. the reason why some shut off valves dont work, is occasionally, fluid gets in the little hole which does not allow the pressure to bleed off. it just builds up behind the drop of fluid until the fluid hits the cutoff valve. that is why after the first cutoff, its difficult to get the pump to go again. but when the level of gas hits the filler tube, (they are designed to have plenty of room in them. most will hold more than a gallon of gas) the back pressure increases which actuates the cutoff valve.

so trickling gas in or pulling the nozzle out and breaking the seal will all cause overfill situations.

easy fix... if you are worried about it or dont feel that you can spare the time, expense and inconvenience, simply dont do either of the two above mentioned steps.

 

<div class='quotetop'>QUOTE(DaveinOlyWA @ Apr 17 2007, 10:23 AM) [snapback]424634[/snapback]</div>

Thanks... Guess my problem was not using the high fill rate and opting for the low fill rate instead. I take heed and make sure I set it to "high" from here on out.

Any thoughts why the pump didn't shut off once gas started pouring out of the fill tube? To be specific... 2-3 gallons of gas flowed steadily from the fill tube, over the nozzle and down the side of the car. The whole time the pump continued to pump more gas in, as the fill tube continued to spill gas out.

11011011

 

I filled up at an Arco in Bellevue, WA last year (2005 Prius, Package 9) and had put about 11.5 gallons in before gas started pouring out around the nozzle and onto the ground. The pump had completely failed to shut off. I cleaned up the mess and didn't seem to have any problems with the car at that point - no check-engine light or anything. And I got over 600 miles on that tank before the fuel warning came up.

Guess I was lucky too.

 

<div class='quotetop'>QUOTE(Dan. @ Apr 17 2007, 11:21 AM) [snapback]424747[/snapback]</div>

deffective equipment is always a possibility since the valve is mechanical, it can stick, but another reason (and more likely) is that the shutoff valve works by increased air flow BACK thru the nozzle. if there is not a seal, it greatly hampers the proper operation so filling with the nozzle not fully inserted besides being illegal, is not recommended.

 

I know this fuel bladder has been discussed in much detail but the question I have about all this is whats actaully causing the damage to the tank?

The pressure from forcing the fuel in?

Or if you top off with say a gas can will this also cause the damage because of the tank being completly full?

Or is it the tank being completly full and then the car sitting in the sun causing the gas to expand?

I always top off I just never fill up and then let my car sit in the sun. I always drive at least 30 or 40 miles after fill up before letting the car sit and it is usually sitting in the garage which is much cooler then out side so I would think additional pressure would not build up.

 

If you go back to the first page, and read the report of Galaxee's DH, she explains the damage that was caused, and how.

 

Could this repair be a DIY'er?

 

When you add gas with a gas can and the gas can nozzle is too big to insert in the hole of the Prius, so you are kind of just filling the area around the gas hole and letting the gas funnel in, could this be a way to ruin a bladder?

 

ok, I just purchased an 08' Prius and so far and really enjoying it. I have been soaking up all this wonderful info from you guys. However, I am a little confused about this bladder in the prius. From the wonderful pictures posted the bladder looks like nothing more than just a flat plastic tank. I picture a bladder and something that will completely or mostly expand when filled or drained. This bladder here retains the same shape, so, WHY is this thing called a bladder?

 

<div class='quotetop'>QUOTE(mlathem1 @ Nov 20 2007, 08:24 PM) [snapback]542279[/snapback]</div>

well, first of all, i guess we have to say, our posted pictures are misleading. the bladder is housed inside a rigid container, and the picture in your mind is accurate

 

OK, reading all this is making me nervous. I am new to the Pri (2 months) and have filled it only about 5 times. The last time I filled it, the pump stopped at a little over 8 gallons and I knew I needed more because I had only put a little over 8 gallons in the last time (on that filling I thought it odd it stopped at 8, but did not want to fill more due to what I had read here). On this fill up I just squeezed the handle and it took a total of 10.08 before stopping the second time. I stopped then. My question is: should I be stopping on the first click or if it is only 8 should I try again? I really don't want to risk any thing like was described above.

 

I am new to this also! My first fill the pump didn't shut off (truck stop set on high-in a hurry) and gas poured out of vent hole onto side of car? We drove home and nothing happened!

Have since filled on low setting and topped off by listening.

Coming back from cub-scout camp in my van and had it set on slowest and it poured out.

Back to the every pump is different.

 

Don't worry about it, and don't top off. 8 gallons should be more than enough to get you around. Even at a crappy 40mpg you'd go 320 miles.

 

We live in the sticks and the wife drives 100 to 300 miles per day for her job!

It goes to 1 pip but hasn't blinked and I filled last and squeezed in 11.01 with out a burp (listened for the gurgle). With 1 left would hope to make it to a station, if I knew the 1 pip was consistant.

Will have to fill on lowest setting and leave it at that?

 

Same truck stop with both vehicles? If so, I would say that their shut-offs aren't working. I find most pumps are overly sensitive to the back pressure caused by the bladder and shut off early. Definitely fill 'by ear' until they get it fixed. However, there is usually so much noise around a truck stop that it could be difficult to hear.

I think it is safe to fill by calculation. My MFD is about 2% 'generous'. If you track your actual miles & gallons, plus the MFD MPG value, you can figure out your % off value as well. You might have some 'flyers' where the tank was either not filled the prior time or the current time. Ignore those and use the ones that cluster near a small % off. Then divide the Trip Meter or Consumption screen miles by the MFD MPG value - the % off (1 MPG in my car). You should be safe putting in at least that many gallons. You might be able to get more in, depending on how full it was the LAST time you got gas.

 

I don't know that the '1 pip' IS consistent. Since you put in 11.01 the last time, if you are getting 50 MPG, you know you can go 550 miles If it hasn't gone to '1 blinking' you must be getting gas pretty soon after hitting '1 pip'. I suppose all Prii could be different, but I think my 2004 goes to '1 blinking' about 25 miles after '1 pip'.

However, mine has had a recall done (applicable to 2004s only) that *I* think also changed WHEN it goes to '1 pip' and '1 flashing' (to keep people from running out of gas, a proposed reason as to why people where experiencing a problem). Therefore, YOURS may not act the same as mine. Mine seems to hit '1 pip' at about 8.5 gallons used, or maybe that is 3.4 gallons left. No need to rush off to the station if I'm getting 50 MPG and have over 3 gallons left.

 

Have never noticed any settings at the pump. I do try to fill slowly to prevent a burp of gas which happened on my second fill up.

 

It did it again last night! Left home for a 47 mile trip with 2 pips and got about 10 miles from town and it went to 1 pip. Pulled in as soon as I got into town and filled on at different location and put in 11.68. Have averaged 44.5 with mostly HWY driving.

I have had cars when you fill, the needle goes way past full, but when it gets close to empty your running on fumes. Others that barely go to full and run forever on E. I wonder if this isn 't going to be one of those go to the station on 2pip cars?

 

11.68 gallons without going well past 1 flashing (let alone NOT flashing as seems to be your case) is a cause for extreme caution. Using your 44.5 MPG average (and was that the MFD value for THAT tank??), you should have gone about 520 miles on that tank. Is that correct? It might be worth having your car checked at the dealer. Not sure WHAT they would check. I'm also ASSUMING that the station's pumps are properly calibrated!!

I would suggest you DEFINITELY fill based on miles and MPG readout. HOWEVER, you do have to be careful. Say you have gone 500 miles at 50 MPG on the 'current' tank. That only tells you ABOUT how much gas you have used (10 gallons), it DOESN'T mean the NEXT 50 miles will also be at 50 MPG. You have to figure the mileage you are getting on the current 'trip' and how many gallons you probably have left. If your calculation doesn't go beyond the amount you put in last time (with perhaps a 5% safety margin), you should be safe. If you put in 11 gallons the last time and are getting 40 MPG on 'this' trip, don't figure on more than 38 miles to empty. Generally I don't try for more than about 10 gallons of 'distance'. I will push it a bit if I know the much better gas prices are in the range of 'how much I put in last time'. In any case, each of us needs to learn how OUR Prius operates!

And, if you are a bit nervous at the bottom of the tank, slow down on the highway. I get 58+ MPG at 55 MPH (and we have a lot of hills to climb and descend) and 48+ at 65 MPH. Given that, I would guess that your 44.5 MPG average means you are running about 70 MPH. You might need those extra ~15 miles on the last gallon