confirmed overfill damage

[DaveinOlyWA]

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.

[Dan.]

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

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. [/b]

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

[KieferSkunk]

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.

[DaveinOlyWA]

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

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.

[bmwquickspeed]

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.

[Rae Vynn]

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.

[esoterikest]

Could this repair be a DIY'er?

[Alabama]

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?

[mlathem1]

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?

[DaveinOlyWA]

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

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? [/b]

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