The Dodge Challenger Message Board

Hi everyone my name is Damien I have a 1970 Dodge Challenger it's been sitting for 12 years but has a solid 383 with a 3 speed torque flight tranny so she starts and runs decent. I have changed the oil before anything tranny fluid looks fine but going to replace it, I dropped the fuel tank and inside is not pretty rust on the whole top of tank on the inside is it still cleanable?? Or new tank ? And if I get a new tank which pump will I need in the tank (very important). I took the rad off because it was gunky and when I drained it and took it off a brown sludge came out from the bottom opening I'm assuming it's sand. the line on the left ( looking into the hood from the front) broke what size line should I get as a replacement 5/8 or 3/5?? If you could help drop a line thanks

You "can" repair tanks or coat them on the inside with POR-15 but to be honest it never really works that well. I would shoot for a new tank if I were you.

There is no fuel pump in the tank. At least not as standard. So unless someone has fitted one it will have a fuel sender unit which has a float for your fuel gauge. 3/8th inch pipe.

The radiator and engine block need a good flushing.
I assume the line you broke was the transmission cooler line? Did you break the fitting or just the pipe? You can just join the pipe with a compression joint.

I'd fit a new tank and sender unit to be on the safe side & not worry about leaks, misleading gauge readings etc.

Also I'd have the rad recored, but do as Dace says and run some aggressive flushing agent thru the cooling system first.
You may find the water pump weeps and you have to replace it, no bad thing cos it's probably got a very corroded impeller so it won't pump well anyway.

Oh and welcome to the best Challenger forum there is

Post up some pics in members cars section, we'd live to see it.

Don't know about POR15 but there are some great products around (in France I use Restom), which do really coat the inside with epoxy resin.
That's what I'm planning to do with my tank, after I have it tumbled for a couple hours with two pounds of gravel inside.
Most of the oxydation in the tank is in the top half, from water condensation.

The other option is a brand new Spectra CR8B (made in Canada if I'm correct).
Don't forget to replace the top padding (between tank and trunk floor), the fuel tank straps (stainless steel available) and J-bolts (which will most probably break on removal or need to be sawed off).

Got a new tank and sending unit now needing help with oxidation in the filler tube, I've got it about three inches up from the bottom of the spout how can I clean or remove this rust I can't buy a new filler neck due to funds is chopping off a 1/4" from the spout a possibility it would it then be to short ?

You have to drop the tank a little to get the filler neck out. Don't shorten it.

Filler neck is ou just need to de rust the bottom end of the pipe what's my best way of going about this ??

Damien 1995 wrote:what's my best way of going about this ??

The problem is that most products might not resist gasoline, so be carefull what you use.
the best solution would be to galvanize the tube after you remove the rust (that's probably the original finish by the way).
Remove rust and scale with a wire brush, use a rust converter (usually phosphoric acid based, it makes rust turn black) or rust dissolver. If you're in the USA, Evaporust from Eastwood is a great product for this. It will remove any original plating though.

you can also use the brazing cream welders use before brazing to tin the bottom of the tube, but you need to clean the steel to bare metal first. It should be rinsed with a water/baking soda mix afterwards.

My buddy said CLR should work fine but I'm not to sure about it what do you think and no I'm in Canada so I have to go to Napa or autozone

I forgot one possibility, you can also try electrolysis to remove rust before a new coating.
The OEM finish was probably terne-plating or ni-terne plating, which is a mix of lead and tin (now often replaced by zinc and tin for environmental reasons). the tube was probably fashioned out of plated steel sheet, so the coating was there prior to the fabrication.

It used to be done mainly by hot dipping in a molten zinc alloy bath, which is rather inconvenient for the hobbyist.

You should be able to find cold galvanizing products about anywhere, look around or ask around to find a good way.
You can also take a look at electroplating, but that will get pretty expensive fast, for a piece as large as the filler tube.

Is the tube finish is largely OK from the top down, you can get away with redoing only the bottom (which can't be seen under the large rubber seal on the trunk floor).

I'd use the same product plumbers use to tin copper tube ends before brazing them (I think it's called "tinning butter" on your side of the Atlantic).
Clean the part with some emery cloth, heat it with a torch, and tin it.
It will be bright silver but it gets dull after a while, like the original finish.
Old-school hot-rodders who use lead use this tehcnique, like Gene Winfield :
https://www.youtube.com/watch?v=87fuTnBS2bE

Fabians right you can get the running products from a hardware store.
We buy quite a lot of plumbing soldering products from the States.
I assume just as easy to get in Canada, the brands we see a lot are La-Co & Rectorseal.
Tinning butter, tallow, it's got a few names