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Dropping tank

TJ1978

I have MANY questions
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How difficult is it to drop the tank on a 78' k5 to replace the fuel sender?

I want to replace the rubber filler neck and metal fuel lines to the mechanical pump.

I've seen cutting the hole on the bed and putting that marine door type thing there. But I'm hesitant to cut the bed.
 
Use a floor Jack and a piece of plywood, not too bad
 
I read this and it seems fairly simple.
I did see to open tailgate to get the straps off
 
With a transmission jack it's pretty simple and straightforward.
 
Easy, except the fill hoses IMO. Don't cut them either, unless you are 100% sure you have replacements. The big one used to be tough (and costly) to find. Not sure if that has improved lately.

I do it with a floor jack and a chunk of wood to cushion the tank, between the straps. Siphon most of the fuel out if its full. You can do it with maybe a quarter tank or so, but it's unwieldy and will shift unexpectedly. Don't forget to disconnect the ground and gauge wires before you start unbolting stuff.

I loosen the strap bolts up front, and remove the nuts at the rear, using the floor jack to keep the tank in place. As long as you don't have dual exhaust (one reason I don't!) you can sit in front of the rear axle, inside of the passenger rear tire under the truck, and undo the fuel/EVAP line clamps with pliers, then disconnect all those hoses. You can remove the clamps from the fill hoses, but if they haven't been off recently, good luck disconnecting them at this point.

After everything is loose/removed that is possible, from the rear of the truck you can splay the tank straps side to side to clear (most likely, or just bend them downward a bit, they will take it) drop the tank a bit until there is tension on the fill hoses, then reach up in there and twist them until they come loose. You can try to break the bond with a screwdriver under the rubber where it connects to the fill neck on the body if it's stubborn. But once you can twist them, they will come free eventually.

Once those pop loose you can just drop the floor jack and yank it out, the straps might be in the way a bit, but the tank will come out.

I put the fill hoses back together with dielectric grease in an attempt to make sure they don't bond to the metal as badly for the next time.

I try to be careful with the cushion material on the tank straps and top corners of the tank, but if they get damaged or need replacement, roofing felt works fine.
 
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Very good write up, screw driver, hooked cotter remover, pick, then a squirt of wd40 between hose and metal.then work the pry tool some more.

If you replace the metal lines go stainless, resist the ethenol/moisture better than steel. Plastic is what new cars use if not stainless.
 
If you have a mechanical fuel pump I would not cut the floor. Its not that hard to drop the tank. I cut the floor in my K5 but I have an electric fuel pump. I wanted easy access just in case a pump failed on the road. With a mechanical pump you should not need tank access very often.
 
Get the fuel level down. The less you have the easier it is. (duh, I know) But you can manhandle an empty tank without a jack. But I've usually done it with a floor jack and a chunk of wood when there is some fuel in there.
 
I just did this to swap a fuel pump on my 40-gal. Took the opportunity to lay down some new anti-squeak pads on it. The kit for that also includes pads for the straps.
 
Lmc has the correct or so it seems filler hose for my 78'
 
I just did this to swap a fuel pump on my 40-gal. Took the opportunity to lay down some new anti-squeak pads on it. The kit for that also includes pads for the straps.
I used some scrap 60 mil PVC shower pan liner I had left over. Something that is very similar to what was originally used is some 30# roofing felt paper (or 15# doubled up). Saves a few bucks for more goodies.
 
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