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Draining fuel pains has anyone done it yet?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by specialtyneed, Sep 30, 2015.

  1. specialtyneed

    specialtyneed Junior Member

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    Question is after searching no one admits yet that I can find to getting tank bladder drained & or fuel system flushed & we need to empty & flush my fuel system of at least 9 month old fuel.
    Has anyone pulled this off yet and have more specific info on pump jumpering? All I need really at minimum is correct ele schematic I can take it from there easily.

    Copied below from a 2008 thread, where Hobbit had outlined this in brief and below is another posters info at botton of thread:

    "For Gen 2, the circuit opening relay is part of an integrated module that is located in the main relay/fuse box next to the inverter. That module is marked with the letter C, and there are no fuses in it. It is next to another module marked with the letter B, which does have four fuses in it. The two integrated modules contain 8 relays total.

    It's not obvious how you can remove module C so that you can bypass that relay to force the fuel pump to run. (The Classic had a separate circuit opening relay, so that would be easy to remove from its socket and place a paper clip across the switched relay terminals in the socket to force the fuel pump to run.)

    Might be easier to look at the circuit diagram and figure out how to apply 12V to the circuit so that you can make the circuit opening relay close and power up the fuel pump. Of course you would have to be very careful not to damage the engine ECU.

    Regarding the fuel line, you might need to remove the cowl running across the engine compartment (where the windshield wiper motor resides), for access to that. Or maybe you can access that if you just remove the relay box mounted to the cowl and the engine wiring harness bracket mounted to the valve cover.

    Look for the fuel rail attached to the injectors, see how it runs between the engine and inverter to the back of the engine, then continue to work your way backwards until you find the quick disconnect fitting.

    If you are interested in DIY, suggest you subscribe to techinfo.toyota.com and look at the electrical wiring diagram so that you can learn about the wiring harness connectors that lead to these integrated modules, and see whether you can DIY or not."

    S
     
  2. M in KC

    M in KC Active Member

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    Can you use a hand pump through the filler neck and skip all the pump jumping.?
     
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  3. epoch_time

    epoch_time Active Member

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    I like M in KC idea..
    I pray I never have to mess with fuel bladder/tank/gasoline..
     
  4. bisco

    bisco cookie crumbler

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    the dealer usually drops the whole tank. big bucks.
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    I've read it's nigh impossible to feed a tube down through the filler neck, to thwart thieves.
     
  6. valde3

    valde3 Senior Member

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    It still is normally possible to get line into the fuel tank. If you use thin enough line. I have not tested Prius but I don’t see a reason why it wouldn’t work. Another question is can you get the tank empty enough if you need to?

    Here if you have diesel car you can be stopped and your fuel tested. They just draw the fuel from the fuel filler (with thin line) so from that we know that it’s possible with (at least almost) all diesel cars. So why wouldn’t it be possible with gas powered.
     
  7. specialtyneed

    specialtyneed Junior Member

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    No there is a anti theft screen and the design swells up to close off the filler neck.



    I know. But if there is a way I am gonna find it.



    This Prius is not like any other north America car on this evil bellows tank particularly same or similar era Toyotas. Some have a plate with holes but this one has a finer screen its been tried bending small tube and rotating multiple stabs and failed.



    I need the fuel pump wire colors and connector location.

     
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  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    In one of my prior posts (which I believe you had copied into your OP) I referenced techinfo as the source for the electrical wiring diagram. I again suggest this subscription website will help as you can download the electrical wiring diagram for your car's model year.

    Although I have had no need to do so, I believe the best way to drain the fuel tank would be to apply 12VDC to the fuel pump after the fuel line at the engine compartment is disconnected from the injector rail and routed into a suitable container to catch the fuel for disposal. Then allow the pump to run until the tank is clear.
     
    #9 Patrick Wong, Oct 1, 2015
    Last edited: Oct 1, 2015
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  9. specialtyneed

    specialtyneed Junior Member

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    This is all I am gonna say here because we discovered gas around the outside of the bellows when removing fill tube connection:

    Remove rear seat cusion assy then pry out cover in center with wiring and disconnect pump & sensor connectors (three). Don't loose rectangle gasket from grey rectangle plug receptical tank mounted side.
    Remove rear canister above axle but first disconnect all vacuum like emission lines bkt, then disconnect ftom tank area at front pass RH side fuel press & return lines, disconnect large fill line (no you can not siphon it fron this point) at RH rear tank last, caution if bellows has gotten fuel outside it will run at a faster than dribble and catch it with tub or pan. There may be a from a cup to couple quarts or more. Ours is at over a 1.5 qt at about 20 minutes in and still dribbling out (update over a gallon now). Use at least 2 people to go rearward and up and to pass side some to clear exhaust & emergency brake cables. Then down & fwd to go out with tank. Here are pics:
    [​IMG]

    [​IMG]
    This above is a swiveling connector with 3 wires and a black plastic clip needing removed vertically then at botton a yellow clip removed by prying with small screwdriver at both ends of the top of it. You will need very short tool for inboard side.
    [​IMG]
    Above is box & lines in ctr rear.
    [​IMG]

    [​IMG]
    Above is pic of fill port. Inside is a whitish plastic solid baffle forcing a 90 degree turn down to a much smaller round hole than the metal tank shell about 3/8" dia and a narrow slot running LH to RH about 30% of the circumfrence in rear area on a horizontal plane nearest aft DR LH corner making siphoning nearly impossible. Can not verify a screen as this may be assumptions of others part. There is also what appears to be a spring steel or CRS (stainless) circlip type retainer ends visible if you blow image up.

    Sorry man, but this is useless info in our case given the last post with pics I made. I am not buying a subscription unless I have to as I feed 6 of us and there are other ways of figuring it out. One reason is I do evrything mobile & the way a lot of them (diagrams / schematics are now set up for printing in books broken up too much or propritetary file systems or for huge monitors causing frustrating navigation problems. Besides in the time it takes to find that site pay them, look that stuff up I will be done with the job.
     
    #9 specialtyneed, Oct 1, 2015
    Last edited: Nov 12, 2015
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  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    No worries, if you prefer to remove the fuel tank in order to drain it, that is your business.
     
  11. specialtyneed

    specialtyneed Junior Member

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    It was necessary due to fuel outside the bladder pumped there before we bought the wrecked car.

     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    Boy that bladder is just a barrel of laughs. :confused:
     
  13. bisco

    bisco cookie crumbler

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    definitely an eye opener, thanks for the pics and writeup!
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    It is possible in that case, that DTC P1455 will have been logged by the engine ECU (of course, any DTC logged by that ECU will be erased when 12V power is lost). If so, that DTC points to gasoline vapor trapped between the bladder and the fuel tank shell.
     
  15. specialtyneed

    specialtyneed Junior Member

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    That is not the words...ahem.... I had for it earlier this evening.

    We have not gotten to read the codes yet due to low 12 aux batt. Was when buying it and jumpering it to move it twice & not starting it yet since purchase. I will be leaving a mini OBD2 / ELMS327 bluetooth reader in it and we use Torque Pro to monitor, read & erase codes. Things may get interesting soon.


    Just added a pic & detailed description of the filler neck and what it looks like inside on tank to the tank removal pic post.
     
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  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You've already done very interesting work by removing the fuel tank and I thank you for posting the photos. A few questions:

    1. When did you realize that fuel had entered the space between the bladder and the fuel tank shell?
    2. What was your means to remove fuel from that space?
    3. There are at least two possibilities to explain how fuel entered that area: a. the bladder is leaking, or b. the prior owner overfilled the tank, thus flooding the charcoal canister which allowed fuel to enter into the space. If a, then the fuel tank would need to be replaced - or else the DTC referenced above will probably be logged. If b, then the system should be OK after the space has been drained and the charcoal canister has engine vacuum applied to it during the course of normal operation, which will purge excess fluid.
     
  17. specialtyneed

    specialtyneed Junior Member

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    Answers to above Patrick Wong's Q's:
    Listed withing each answer in order of importance.
    1. When I decided that after inspecting tank & pump configuration it was not conducive to draining fuel by powering pump due to a much greater number of wires than is on any other vehicle in North America that I have ever worked on due to schematic availabity being an severe inconvience. The bellows tank being a seemingly inigma mystery no one seems to post much evidence real experiene dealing with. Lack of proven alternate established methods outside of dealer shotgunning of draining or maintaining tank, canister & pump. Given the commonality of how often the bladder gets fuel overflow condition and history of the driver being poor and it being a company issued vehicle the chances of abuse causing this bad tank probem were very high. If I pumped it empty and still had fuel in between shell & bellows then tank would still need pulled wasting the pumping effort.

    2. The fuel runs out in a small stream due to bellows pushing it out, physics of surface tension & fuel floating on denser objects (bladder) when not allowed to flow lower around it due to lack of space from spring like action of bellows. We helped scavange it all tilting it up in ever invreasing angles every 40 minutes or so for next several hours using objects to block it up over a pan.
    3. I have scoured the internet and the likelyhood of the bladder rupture based on the severely lacking of high quality of owners descriptions reporting the problem verses the human error, (human factors) and ingorance and blame game, verses Toyotas quality problem defect percentage being very low its a safer statistical asumption (given I never like to guess it was my best gamble) the tank bladder was flooded. Simply put Logic based elimination. Agreed about casister. If when refilling tank we get fuel guage failing to be accurate after calibration cycle and tank does not take normal qty then we will have confirmed ruptured bladder but we are not doing that unless we have to. There are 2 at the salvage Gen 2's so no biggie just not wanting to waste a dime at this point.

    Was kinda under the impression these issues were getting pretty obvious but not everyone is willing to get as dirty and banged up learning as us. Just IMHO. Thanks for the curiousity.

    We are at over 5.5.. no edit see pic for technique for when tank is mostly empty update over 9.7 ish gallons removed.... If in unlikely case bladder is ruptured we will do & post a Youtube style tear down vid cutting it open near the center flange while purging vapors.
    I am very sure he did a fill up right before the wreck now. Had to explain to the boys why fuel does not slosh. Finally going back in with tank. About 26 hours later of which about 6-7 hours was slow draining. Man that evil fuel guage calibration circuit :-(

    [​IMG]

    Tank is going back in now...

    Sent by a
     
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  18. bisco

    bisco cookie crumbler

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    looks complicated, i wonder how much toyota saved by eliminating it.
     
  19. specialtyneed

    specialtyneed Junior Member

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    Leak check today.

    Attempting starting, & of course problems:
    HV batt reads erroniously 1 bar most attempts but one time it read closer to correct at all blue bars. Once ICE ran rough for about 6 seconds. Lots of dummy lights, Air Bag, ABS, VSC, (car on curvy road light ?), Maint Reqd, Main Batt light, all the time & red triangle and high pitch beep most the time. Basically all heck. Ready light does flash but it does not go into gear all attempts but three so far as noted below. Pulling white connector, to reset. Will do aux batt disconnect to reset if no help...Red triangle went away with white plug reset but HV batt indicator is still giving diffrent readings only once again correct at most blue bars. Lots of relays and pumps running under hood sounding mostly normal like our '04 Gen 2. Start button only gives me a yellow LED. Read a P0A80 replace HV hybrid drive batt pack code but its pending.She did go into drive EV electric mode only once and tried to move but I had emergency brake set but no ICE. Red triangle back now.... Having the aux batt disconnected for 5 minutes....Still no help except ele hybrid drive engaged once but ready mode is not flashing & she will not go into drive except the once this post reset. Its dropping out of drive like our '04 did right after buying it when the aux batt was low from idiot detailer & we had severe trouble getting it into drive and ran HV batt very low after it sitting a while on dealer lot before a brief test drive, then detailing & grief at gas station a quarter mile away when dash failed and only aux starting procedure would work.
     
  20. Mendel Leisk

    Mendel Leisk Senior Member

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    So you're almost out of the woods? :ROFLMAO:

    I saw a video once of the Prius assembly line. There was some kind of Nintendoish music playing in the background. It was very clean, obviously. The workers had a lot of specialized tools, robotic arms. Some were even sitting on little seats on arms, that zoinked into the vehicle for install of this or that.

    Basically the antithesis of your situation: the grubby/dusty aftermath, balancing a knackered gas tank on the edge of an old chopping block.