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Old 01-18-2012, 10:55 PM   #1
IOWNATRUCK
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dropping the gas tank?

my truck makes a popping metal sound as if the throttle is popping back or something and then bogs down on hard acceleration and then regains full power suddenly any ideas???? also im thinking maybe bad or low gas is contributing to that, is that even possible? but how is dropping and cleaning the gas tank tough job? how do you go about it?
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Old 01-18-2012, 11:12 PM   #2
THE "10" SILVERADO
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Re: dropping the gas tank?

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Originally Posted by IOWNATRUCK View Post
my truck makes a popping metal sound as if the throttle is popping back or something and then bogs down on hard acceleration and then regains full power suddenly any ideas???? also im thinking maybe bad or low gas is contributing to that, is that even possible? but how is dropping and cleaning the gas tank tough job? how do you go about it?
Thanks.
Cannot really answer your first question but I dropped my gas tank to replace it a couple of weeks ago. Instead of trying to loosen the straps, just unbolt the 8 bolts to the strap brackets off the frame. First though put a jack on the tank and take pressure off the straps. Then once the bolts are out just lower the tank. Be sure to disconnect the rubber fuel lines that go over the frame to the inside rail as they will tear lowering. (mine did cause I forgot to undo them). Also disconnect the fuel sender ground on the inside of the frame. Real PITA but I didn't want to remove the bed. Once you get it down and know how to do it, it will be really easy reversing the process.

Good luck
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Old 01-18-2012, 11:39 PM   #3
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Re: dropping the gas tank?

If it's never been down, the rubber hoses are probably shot and they will remove themselves. That's OK, you should replace them anyway. Like said, drop the tank by removing the brackets from the frame and don't forget to unbolt the ground wire for the sending unit.

With the bed off, it's very easy to hook up the fuel lines. But with the bed on you can run longer fuel hose, and let it loop around itself as you raise the tank back into place.
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Old 01-19-2012, 12:54 AM   #4
gramps77
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Re: dropping the gas tank?

Do you have dual tanks? Mine had similar symptoms but I changed the valve that switches between the two and it runs GREAT now. I did also replace my fuel lines while I was at it. As was mentioned, dropping the tank by removing the 8 bolts that hold the straps on was easiest. I made sure the tank was as empty as I could get it, left one bolt in each strap, then I held it while my wife finished removing the last 2. It was fairly easy to drop from there
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Old 01-19-2012, 09:44 AM   #5
Turbo85GMC
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Re: dropping the gas tank?

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...with the bed on you can run longer fuel hose, and let it loop around itself as you raise the tank back into place.
That's exactly what I did. Got the new fuel lines about twice as long and looped them, it worked great!
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Old 01-19-2012, 01:08 PM   #6
Texasupton1
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Re: dropping the gas tank?

Dito for all you say, but the main fuel line on mine kept kinking. Long nor short would not work. I finally got about a 2 ft. piece of the high pressure line and ran it from the sending unit, over the frame, up inside a crossmemeber to the other side of the truck where there was a section of metal line that goes to rubber and back to steel. I ran the new line directly over and connected to the steel line and it worked great. In other words, i bypassed the section you would hook onto up above the tank. If I would of done this to start with, the job would have really been easy.
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Old 01-19-2012, 10:11 PM   #7
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Re: dropping the gas tank?

If your truck is a 2WD with the 20 gallon tank, I would lift the bed.

I got the joy of doing the job twice with the same tank. The first time, I dropped the tank, and then experience pure @#$@ trying to install the tank back into place. It took only around an hour to drop it, and then 3 hours of back breaking labor getting it back into place.

Lifting the bed is a piece of cake, even with just one person. All that you need to do is remove the 8 bolts, and then jack up the front of the bed 6".
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Old 01-19-2012, 10:29 PM   #8
IOWNATRUCK
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Re: dropping the gas tank?

thanks for all the help, dropped it today, haha didnt seem to dirty which was kindof irritating after laying on concrete for hours dropping it ha, now any reinstallation tips or special things to do or pritty much just straight forward?
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Old 01-19-2012, 10:49 PM   #9
THE "10" SILVERADO
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Re: dropping the gas tank?

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Originally Posted by IOWNATRUCK View Post
thanks for all the help, dropped it today, haha didnt seem to dirty which was kindof irritating after laying on concrete for hours dropping it ha, now any reinstallation tips or special things to do or pritty much just straight forward?
Make sure your brackets are in the right place at the right angle. I torqued my front strap to far and put the bracket at an angle so I didn't fit right on the frame. Ended up having to loosen it to make it work.
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Old 01-22-2012, 01:12 AM   #10
lap15
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Re: dropping the gas tank?

Whenever you get a truck of this vintage it's always a good idea to drop the tank, clean it out and replace the fuel lines. I did this to both my '75 and my '79 (going to do my '86 this spring) and it makes a big difference with how they run. It's easy! Don't mess with the straps! Unbolt it from the frame by removing six of the eight bolts. Loosen the last two but keep them in. Most bolts have grease on them from the drive shaft so they should not be rusty and come off easily. Don't worry about the fuel lines-but be careful with the sending unit wires. I agree 100% with either lifting the bed or taking it off completely. I did it myself with no help. Just take your time. Make sure your tank is as empty as possible. I tied it up (front and back) with some twine to hold it while I remove the last two bolts and lowered it onto a thick cardboard box. Then I cut the twine and gently lowered it down. Unhook your wires and you're good to go. Once you have it out, tape off the lines, hose it off and scrub it with some cleaner. Check it carefully for pinholes or leaks. When it dries take a screwdriver and hammer and tap off the lock ring and gasket and remove the sending unit. Make sure the float is free and looks good. Clean the pick up screen with some solvent and set the sending unit aside. Drain the tank, let it dry, and wipe it out with some solvent that will evaporate completely (I use surface prep). Once tank is clean, give it a nice coat of paint and reinstall. Getting it back in is easier because it's empty and a lot lighter. I use the same technique. Slide a box or something under it to lift it up. Make all of your connections (hoses & electrical)- I actually added 6 or 8 inches of fuel line to make it easier. Line up and put one bolt on the front and one on the back to hold it up. Line up the other bolts and tighten them up- that's it.

Last edited by lap15; 01-22-2012 at 01:24 AM.
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Old 01-22-2012, 12:48 PM   #11
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Re: dropping the gas tank?

I was going to ask how to replace the fuel pump on my 87. It seems like I would have to raise the bed to disconnect the wire to the pump and the sender unit. My pump is OK for now, but if I replaced it what brand should I get? And does anyone have pics of the tank removal?
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