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Does upside down gas nozzle hurt car?

Discussion in 'Gen 2 Prius Technical Discussion' started by Aegison, Jan 5, 2010.

  1. David Beale

    David Beale Senior Member

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    The tank that was opened by Galaxee's husband (or Galaxee, as he also uses that name) had a hose popped off. The bladder was fine. It's unrepairable, however. He had to cut it open to see what happened.

    As far as escaping vapours, how about the escaping vapours when you fill the tank? We don't have the extra rubber capture device (thankfully, so we can actually -SEE- what we are doing when we fill up!). How about the vapours that escape when you get a bubble back spill (which happens frequently with Prius filling if you do it the way everyone tells you to)? How about the vapours that escape when they operate the oil well?

    Please! Think about it! Almost nothing "escapes" in the 10 km or so I leave it loose as the surface area of gasoline is very small, especially when the tank is full.
     
  2. DetPrius

    DetPrius Active Member

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    So, this time of year when the gas goes in at say 50 degrees, and I drive away and it cools to 20 degrees, does the volume shrink by the same amount it would have expanded to if it was 80 degrees OAT?
     
  3. Politburo

    Politburo Active Member

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    There should be minimal vapors coming off the fill neck during filling. Displacement emissions are controlled using the ORVR system.

    I would disagree that bubble-back spills are "frequent". But you are correct that we're talking about emissions on the order of fractions of an ounce.
     
  4. David Beale

    David Beale Senior Member

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    Yes, the fuel does shrink. Note that most pumps have a sticker on them that says something like "volume corrected to xx degrees temperature".
     
  5. Rokeby

    Rokeby Member

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    Once more to the well. :rolleyes:

    See attachment in post #15, and

    See the NOTE below: ;)

    fuel bladder.jpg

    From here. Everything you wanted to know about the Gen II fuel/evap system.
     
  6. CharlesJ

    CharlesJ Member

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    Actually, if I found the right coefficient of expansion for gasoline,
    http://ts.nist.gov/WeightsAndMeasures/upload/B-015.pdf
    and crunched the numbers correctly,

    0.00069/degF I think that 20F change be about 1/2 liter;):D But, my cruncher may be off:eek:
    If not, that is not a lot of expansion and, by the time one gets home, etc, it is a draw.
     
  7. CharlesJ

    CharlesJ Member

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    Besides the fresh air line that goes into the space between the bladder and the shell, there are two vent lines but both are at about the 12 o'clock position and close to the opening. For fuel to get in there, you'd have to completely fill the filler neck all the way to the cap opening and higher to get into those vents. Not impossible of course but one has to try hard and fuel would be flowing to the ground by then at the nozzle.
     
  8. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    as far as how the shutoff works, as i understand it, the filler tube hows a gallon in itself. when the tank is full and fluid starts to fill the filler tube, that is when the auto shutoff happens.

    so, that means that yes, you can EASILY put in another gallon because the tube holds that much and should be empty if the shutoff worked properly. now, when filling, the gas is sloshing around, causing a situation where the opening of the tank could be covered, causing the auto shutoff to happen early meaning that a some gas can be added without actually filling the tube.

    another thing to consider (and something that happens to me about 10-15% of the time) is either a defective auto shut valve, OR, the person before you, overfilled his tank, causing fluid to backup in the auto shut off valve making it not work correctly.

    so because of that scenario, the most important thing about filling your car is KNOWING HOW MUCH GAS YOU ARE REPLACING
     
  9. fayeweezer

    fayeweezer New Member

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    Inserting the nozzle upside down will allow the tank to be filled more because the sensor is higher in the tank resulting in a fuller tank which is not a good thing! besides, i would never try to fill upside down because i m too afraid of the nozzle falling out.
     
  10. alanh

    alanh Active Member

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    The other issue is that in areas that have vapor recovery nozzles, inserting it upside-down can cause liquid gas to be sucked into the vapor system. You're paying for gas that you're giving back to the station. :)

    Older ones used the rubber boots around the nozzle. Newer ones have a vacuum system that sucks fumes through some holes in the side of the nozzle.