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Draining fuel out of the tank?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fortcollinsram, Jul 11, 2002.

  1. fortcollinsram

    fortcollinsram 1/2 ton status

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    Well I am installing my ORD shackle flip today...But I think I may have to drop the fuel tank...problem is that it has about 15-18 gallons og fuel still in it...any tips or tricks to temporarily drain the fuel into another source (buckest or trash cans or something)? Thanks for the help...
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Drive it? /forums/images/icons/smile.gif

    I would disconnect the fuel hose up front, at the fuel filter, or near the tank and let the fuel pump pump it into a suitable container. Electric fuel pumps make this so easy : )
     
  3. rampage

    rampage 1/2 ton status

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    If you let the pump do it then it will take some time. I filled a couple of 2 gallon tanks this way and each one took about 15 mins. After you turn the key to the accessory setting the pump only runs for a few seconds (to pressurize the system) and then shuts off. You then need to wait about 10 or 15 seconds before you do this again or the pump won't try to 'prime' the system. It's possible to do it with the pump, but there must be a better way.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Yeah, disconnect the pump wiring at the connector by the tank, run a wire straight from the battery + to the correct wire on the pump (12V in, ground to frame, and fuel tank sending unit wires only right? So should be black, pink, and the leftover wire gets 12V IIRC) and have at it. I did this with a tank OUT of the vehicle, but in, should be able to do this with only one 12V wire. Whatever GPH rating of the pump is, (must be known by someone) obviously if its 30GPH it would take 30 minutes to drain half a tank.

    Only other way is to siphon it that I can think of, and on a TBI setup this isn't easy, the lines aren't just hoseclamped like on the carbed setups of course.
     
  5. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    </font><blockquote><font class="small">In reply to:</font><hr />
    Only other way is to siphon it that I can think of, and on a TBI setup this isn't easy, the lines aren't just hoseclamped like on the carbed setups of course

    [/ QUOTE ]
    Actually, some TBIs are just hose clamped at the thank. Most of the other stuff is metric o-ring but, at the tank, they use FI rubber hose and clamps.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Really? I'll check again, but I'm pretty sure that my fuel out line is a threaded flexible line at the tank for the TBI setup, (1989 supposedly) and the fittings that are hose clamped don't do anything more than empty into the top of the tank, making them unusable for siphoning.

    Besides, if that were the case (hose clamp on fuel out line) then you couldn't use all the TBI sending units for TPI, which is what I planned on doing (now I have to REALLY look lol) and what is done with TBI Monte Carlo tanks on TPI swaps. I've got all the lines and sending unit in my garage, I should know in about 3 hours.
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    I just checked, both the fuel out and the fuel return lines are threaded pressure fittings. The vapor fitting does not extend but 2" below the top of the tank, but the return line goes all the way to the bottom with the pickup.
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Well, I'm basing my statement on the early TBI tanks I was looking for when I did the TBI on my K30. I originally wanted a bolt on saddle tank that had baffles and sending unit for TBI. I eventually adapted a TBI pickup to my diesel saddle tank. The 87 saddle tanks used a double worm drive hose clamp (actually made as 1 piece) to hold the hose on the high pressure line. I eventually found 3 of them (87 saddle tanks) and they all had rubber hose. But they also had busted plastic baffles so I passed on them. I also found some later K5 TBI tanks (I think they were late 80s) that had rubber hoses and clamps. However, all the inside-the-rail TBI (truck) tanks had fittings (IIRC) and most of the K5 tanks have the threaded fittings, but not all. I myself am running one of the sending units from an 87 TBI saddle tank right now and it has rubber hoses with clamps. I looked through many, many tanks trying to find one to use, and I’m just saying that *some* didn’t use the fittings, I agree that most did…
     
  9. reddog64

    reddog64 1/2 ton status

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    um... syphen???? just give it a good suck and watch all 18 gallons pour out...

    worked for me...

    oh open the filler up too
     
  10. 70~K5

    70~K5 1/2 ton status

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    I have a big ice pick, we can get that tank drained real quick. /forums/images/icons/grin.gif /forums/images/icons/grin.gif /forums/images/icons/grin.gif /forums/images/icons/grin.gif
     
  11. 90K5

    90K5 1/2 ton status

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    I'm with Reddog...sometimes ya gotta bite the bullet and do it the hard way...make sure you use a clear tube so you can see the gas coming, and blow into the tube before you suck...besides, gas won't hurt ya/forums/images/icons/wink.gif
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

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    Areyou talking siphoning from the fill tube or the fuel out fitting? I've never had a piece of hose long enough to go through the fill tube, is it pretty easy to snake it down into the tank?
     
  13. rampage

    rampage 1/2 ton status

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    Not really. I think most modern cars have a screen blocking the filler tube that also helps prevent people from stealing gas by siphoning.
     
  14. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I don't think your going to be able to siphon from a late(er) model gas tank. They have various things added to make sure you can't siphon from them.

    As for the rubber hose TBI sending unit, here is a pic of mine showing the rubber hoses along with the pump/guage wires. Here is the double clamp. I've never seen it anywhere but on the early TBI units.
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    I know I'm gonna sound like an ass, but that doesn't look like ANYTHING GM would do. I've never seen GM use double hose clamps, nor have I seen GM use that type of "cheap" chain store hose clamps. The hose doesn't even look like something GM would use.

    I mean if you've seen it multiple times, that more than likely means its stock, and you can't doubt your eyes. Don't know what to say. If that was the only one I'd seen like that (such as me right now) I'd say no way it was stock.

    Why is the steel line so tall here: http://www.members.cox.net/russhuffman/junk/clamp.jpg I can't figure out if this is mounted in the frame or? How were they attached to the "hard" line at the frame? (because GM would never use rubber hose at the frame) Same way? Any evidence of tampering there? That bolt in the vapor line, unless you did it, obviously wasn't stock : )

    Seriously, I know this is being drug into the ground and has little to do with siphoning the tank, but I am really curious to get to the bottom of this. Of course, an '87 parts manual would get me to shut up, but I don't have one : )
     
  16. trailblazer87

    trailblazer87 1/2 ton status

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    Go out and get some big medical tubing, all k5's were built prior to addition of anti-siphon screens /forums/images/icons/grin.gif
     
  17. reddog64

    reddog64 1/2 ton status

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    hey dorian.. I'd syphen from either of them.. i have doen it from the filler before...
     
  18. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Sorry to be so long replying, I'm out of town...

    Anyway, I've seen the double clamps more than once. One is on the truck that I pulled my donor out of, I have it and it is in the line pic. That was an 87 Chevy TBI. I remember seeing it on at least one other. It was notable because I had never seen a clamp like that anywhere else. Those clamps are actually 1 piece, joined under the worm/screws with 2 separate slotted belts. Never seen a double clamp before I started looking for tanks. Most of the other tanks with rubber hose type senders were already loose or stripped, but they were definitely factory GM with in-tank pumps. The pic I posted clearly shows the sending unit with the wires built in. The tank is on the ground. If you want more (better) pics or part numbers or anything, PM me and I’ll get what I can when I get home.

    As for the lines, the rubber lines go from the hard line on the frame to the tank sender. Those hard lines I cobbled together to have a temp tank setup to move my truck while I'm working on the body. It is definitely not stock. /forums/images/icons/laugh.gif BTW, the clamps in the tank pic are just cheap worm clamps. The only odd-ball (one piece) clamp I have is the one that is on the other pic that you referenced (that’s the only reason my temp lines were shown). The rubber line and bolts are there just to keep the lines clean while the tank is off. The rubber line that is used to actually hook it up is rather expensive EFI rated rubber line from NAPA. Other than jumping from the frame mounted hard lines to the tank, all other connections in my fuel system are metric o-ring.

    It’s late, I hope that makes some sense. Unfortunately I have no manual for 87, I just figured that was how the early units were done since I saw it on more than one of the tanks. Maybe I’m confused or something. I also apologize for taking this further off topic but, like you Dorian, I’m now curious about the reality of something I had thought I knew. Your questions don’t bother me at all, I may have made assumptions or misunderstood what I saw. Wouldn’t be the first time. Maybe some (all?) of these were electric pumps for carbs or something? I don’t know… Has anyone else EVER seen a TBI sender that used rubber lines to jump to the frame hard lines? If so, what was it on?

    I guess all I *know* for sure is that I have in my tank a GM sender, with an electric fuel pump, and rubber hose nipples. It worked with my TBI and I replaced it with a new TBI pump by asking for a TBI pump from an 87 K10 (the donor). I also *know* I saw that on a couple of different GM tanks with fuel pumps in the tank, that includes rear center tanks like Blazer/Suburban tanks. However, the vast majority were threaded o-ring fittings. Oh well…
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

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    My one question after re-examing this http://www.members.cox.net/russhuffman/junk/TBISU.jpg is whether you are implying the 3clamps easily visible in that pic are the "factory" ones you speak of, or if there is one on that center hose that is kind of dark and hard to see.

    I know a few different GM "hose" clamp styles but http://www.members.cox.net/russhuffman/junk/clamp.jpg I don't see those as being anything more than standard hose clamps that I've never seen GM use on anything.

    Don't think GM ever did a V8/carbed electric pump setup, but what I don't get is, even if hose clamps *were* stock on some TBI trucks, why an '86 TBI Monte Carlo (exact same sending unit setup as on an '89 K5 for example) didn't use hose clamps. Probably even an '87 Service Manual would have a picture of the sending unit, or how to remove it, which would tell how the hoses come off...apparently, no one has either, or just doesn't have the inclination to look : )
     
  20. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    All those are common cheap clamps except for the one odd-ball "double" clamp shown here. When I get home, I'll pull it off and take a decent pic. I'll also try to get a decent pic of the sending unit too and I'll start a new thread so we don't take this further off track. Maybe someone with a service or parts manual will reply eventually... If you don't see a new thread start for this by middle of next week (I'll PM you), send me a PM and I'll get it started so we can look at it further. I'm really currious now as to what the devil I have here. If I'm right about where they came from, it would be good to know where they are available for those doing conversions.
     

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