Hello, I am attempting to replace the main fuel line in a 1972 cutlass hardtop that was my dads. The car has been sitting for 40 years in a garage and the fuel tank was just a mess, laquered up and rusty on inside. The fuel pipe connecting to the tank has rust on the inside so i would like to replace the old fuel line with a new fuel line. I ve replaced the brake lines through the rear cross member. Im working my way forward replacing brake lines, fuel lines, brake parts and front drums to discs before i get to engine and have it looked it before turning over
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So i am wondering about the following:

1. is there a way to clean the old fuel line instead of replacing it? What would you do to a car thats been sitting for 40 years in a garage?
2. should i replace the evap line as well that runs beside gas line? I was going to replace gas line but not evap line.
3. if i do splice the stainless steel gas line, (i was thinking above the control arm where the frame levels out) could there be any flow issues? Id rather have a non jointed fuel line but i am hesitant to lifting the body off of the frame.

thanks in advance. I can post pics soon.

specs 1972 cutlass s hardtop
1967 400 E block with B heads 11.5:1 compression
750 holley
4.11 gears 10 bolt 8.5 rear
3 speed B and M transmission reversed manual setup 123

 

After 40 years of sitting, the only thing probably keeping the lines from leaking in the crud inside.

It’s a pain in the butt to change, but bite the bullet and replace it all.


Assuming the car is solid, it’s not that big a deal to lift one side of the body off the frame. If you have any doubt that the bolts will come out without drama, drill a tiny hole above each caged nut for the body bolt. Spray lots of rust penetrate, let it set, then spray it some more.

If you would rather not chance it, you could splice the line. Ideally you should flare the line end so the hose and clamp has good seal.

Another option, A/C Delco has a fuel hose that’s modern fuel compatible, is rated for both carbureted and fuel injection, and has reinforcement fibers molded into the rubber for strength. Use lots of clamps to support and locate the hose, problem solved.

 

Most stainless line is hard to double lap flare. The easiest way with the body on the frame is to get the 5' pre-fab lengths of line, and use brass couplers. You can put a bulge at the end where hose goes on with your flaring tool.

 

thanks for information. I was thinking the line is fairly good since the car has been garaged and was undercoated back in the day. The line looks like it has a little rust staining on the inside end closest to the tank. I may push some alcohol through the lines and see what happens.

I was considering supporting the body with jack stands with plywood support and lowering the frame from the body so I would not need to jack up the body from the frame but drop the frame from the body while the body stays level.

 

You will need to remove the fan/shroud, maybe some hoses, wiring, and possibly the shift linkage.

I would think you would only need to raise one side of the body, and only a few inches. Whatever you do, you need to raise the body or lower the frame evenly.

 

Check out The Right Stuff Detailing or Classic Tube for prebent, stainless line. Yes, it is absolutely necessary to at least flush, if not replace, all the chassis fluid lines. The metal was better back then, but it is still raw steel. The new NiCop/conifer line is corrosion resistant and easy to bend and flare. That may be an option to explore, as well.
Most importantly, make sure to replace any hoses that are rubber.

 

Disconnect at fuel pump, disconnect at tank, run some fuel back thruline into a CLEAN bucket or catch can a couple times, discarding the first one obviously so you can see what the second one looks like, look at the fuel..if its still very dirty or has particles, best replace , if its clean, leave it alone.. just because the tank rusted after all those years does not mean the gas line did the same.. I have yet to replace a fuel line in an old car unless it had debris coming out after flushing it.. that was once,years ago because car sat lopsided in a field forever.
Once you replace the tank and the fuel line connecting tank to main line, a new fuel filter will take care of any concerns..