71 Challenger Gas Tank Removal?

[dblevene]

Hello everyone...

Newly registered here, but a long time reader.  I have a 71 Challenger that was sitting for 6 years stuck in my divorce.  I'm kinda embarrassed to even ask about this, because I know my car blind folded, but it's just something I have never tackled before. I need to get the tank out, as I think the fuel has solidfied and will need to clean out the tank, replace the sending unit, blow out the lines, replace the pump and rebuild the carb.  Miraculously with a new battery, the car started with a shot of either and then some gas down the carb it built perfect oil pressure, but there was no draw of fuel even after putting some in the tank.   I took the valance off and drop the nuts on the studs to the bottom of the threads and the tank seems ready to come out.  However here is my question and concern.  The tank has never been removed and even still has the paper tag on the sending unit in perfect shape.  How do I disconnect the keystone clamps and get the line off the sending unit?  Also there is 4 lines with keystone clamps on the right side of the tank, do I need to remove these as well to drop the tank?  Do I need to drop the mufflers to get to any of these?  The filler neck looks pretty simple to take care of, so I'm not concerned there. So far without any WD-40 or penetrants everything has come apart pretty easy and looks in great shape.  The car has been garaged pretty much it's entire life and has not seen rain in almost 30 years, and I own it 27 so that probably helping make things a tad easier.   Any help or advice woiuld be greatly appreciated.

Thanks, Dave

[MEK-Dangerfield]

Dave,

   My first thought is your fuel pump might be a goner. You can disconnect the input to it and run a rubber line to a gas can to test my theory out. If it doesn't pump after doing that, then we'll start with a new fuel pump. They have a rubber diaphragm, so it might have dry rotted from sitting. Speaking of dry rot, how do all the other rubber lines look and feel(in the engine bay as well as coming from the gas tank)? If they are very hard, change them out because they might have a crack letting in air.

I'm just trying to give you possible options where you don't have to drop the tank.

[burdar]

Keystone clamps are one time use.  You can't save them.  Your rubber lines are most likely rotted and need replacing anyway so just cut them.  You can work on removing the Keystone clamps after the tank is out.  Save that paper tag on the sending unit.  That's something to keep in the safe.

[dblevene]

Dave,

   My first thought is your fuel pump might be a goner. You can disconnect the input to it and run a rubber line to a gas can to test my theory out. If it doesn't pump after doing that, then we'll start with a new fuel pump. They have a rubber diaphragm, so it might have dry rotted from sitting. Speaking of dry rot, how do all the other rubber lines look and feel(in the engine bay as well as coming from the gas tank)? If they are very hard, change them out because they might have a crack letting in air.

I'm just trying to give you possible options where you don't have to drop the tank.

I'm thinkin' the fuel pump diaphram definitely punch through when I cranked the engine for the first time in years.  But as I poured 3 gals of gas in the tank (why I didn't just put a gallon in is beyond me) because the gas guage read empty, The smell of rotten gas was comin' back in my face. I should have stopped pouring at that instant.  The fuel lines all look good.  Not soft, but not hard as a rock like a dry rotted one would be.  No visible cracks either. No doubt the sending unit screen is probably clogged with syrupy goop and the float stuck in it too. I'm just hoping I can get the steel fuel line clear at this point.

Keystone clamps are one time use.  You can't save them.  Your rubber lines are most likely rotted and need replacing anyway so just cut them.  You can work on removing the Keystone clamps after the tank is out.  Save that paper tag on the sending unit.  That's something to keep in the safe.

Good idea on cutting the fuel line as I was gonna replace the rear connection kit and ground strap anyway.  I just am concerned about cutting those 4 lines on the right side.  Anyone know if these lines have enough play to drop the tank without disconnecting them?  Also any experience on replacing the keystone clamps once the tank is back in? 

[torredcuda]

You`ll need to disconnect the 4 lines also.Either use screw clamps or if you want to stay factory correct you can get the keysonte clamps,there is a special tool for crimping them.

http://cgi.ebay.com/ebaymotors/Kent-Moore-J-22610-Keystone-Clamp-Plier-_W0QQcmdZViewItemQQitemZ170665624678

[DocMel]

Removing the tank is easy  It waill take you about 30-45 minutes

Remove all fuel lines going to and from the tank, at the tank.  Remove sender unit wire at gas tank sender

Remove the rear valance:  Very easy.  About 5- bolts facing the rear under the rear bumper  (Easy to get to)

Remove the inner rear valance bolts that holds the valance to the rear 1/4 panels.  There are about 2-3 on each side. 

Remove Valance  (The most frustrating part here are the tab like "fender nuts" that hold the bolts on.  They rust easy, and will prob break.  You can get them at Lowes/home depot or Autozone..   Some of the bolts heads will be a little hard to get to, but not too bad

Get a f riend to help:  Tanks are somewhat heavy empty:  I guess more akward than heavy.  If any gas is in it, you will need the extra hands:  Remove gas tank straps at the rear of gas tank.  There is one nut on each strap.  It will take a very deep socket, or you can use an open end wrench to get them off   Note where the strap j bolt fits in a slot at the top.   Once you loosen the nut, eventually you can get enough slack to lift/remove the strap bolt out of the slot

Slide tank downard slowly, noting the gas tank neck needs to slide off the rubber donut at the neck

you are now done.   Look inside the tank at the neck and where the sender hole is.  Im sure you will see a mess  Remember, stock tanks are about 40 years old now

[Bullitt-]

I would suggest some penetrating oil around the filler neck grommet or it may tear.
New grommets are available but I tore what was probably a reusable original

[GranCuda1970]

Yep, I tore my origional as well it was stuck hard but luckily you can still get em. Classic industries has em. I am now in the process of putting in the fuel lines. waiting on the hanger clips to arrive 3/8's clips. The gas tank on the barracuda was pretty easy installing I repainted the tank and straps they were origionally just stainless but I painted the straps cast and the bottom of the tank argent silver looks really niced but not origional look. Installing the sending unit without the tool was difficult but I got it in with 2 flathead screw drivers a few sware words and elbow grease. I ordered the 1/4 return line with the water vapor separator , I don,t think I need them in 1970 they did not have em, (I thunk) and someone swapped my origional tank out for a later model tank ,( has the 4 nipple tubes sticking out the side of the tank ) but will put them in when I find more info on where the separator is mounted and with what bracket?  Fuel system info is hard to come by!!... could not find info in the 1970 book either or the cuda challenger restoration guide. Need to actually see one and take a picture to see what to do.

[dblevene]

All great info here! Thanks!  So far everything has come off super easy.  I just have to pop off the fuel line and the 4 vent lines and then drop the tank.  I think I am gonna use  standard 5/16" fuel hose and regular clamps to replace the fuel line too sending unit piece, until I drop the tank for a full resto where I will use the proper fuel hose and keystone clamps.  I imagine no matter what clamp you are putting back on it'll be a tough and tight situation.  The 1971 service manual says that the right side muffler and tailpipe should be dropped and the heat shield removed. I'll see how this goes.  Hopefully the grounding strap comes off with no issue; it seems to move on both sides, so I'm guessing that'l be ok.

[TreeFrog]

You`ll need to disconnect the 4 lines also.Either use screw clamps or if you want to stay factory correct you can get the keysonte clamps,there is a special tool for crimping them.

http://cgi.ebay.com/ebaymotors/Kent-Moore-J-22610-Keystone-Clamp-Plier-_W0QQcmdZViewItemQQitemZ170665624678

I used fuel injection clamps, they are the same price as washing machine clamps, but looked more like automotive than backyard.  Now who will be looking up under the car... no one, but it made me feel good