This isn't too difficult to do, but I can't be 100% sure that 4' of tubing is enough. Here is what I suggest. If the 4' section is pre-made (fittings already on it), I would choose to go in a different direction.
I would suggest getting a nickel/copper replacement brake tubing. It will never rust and is much easier to work with as far as bending. Get a section of that type of tubing and the two fittings (one at each end).
Next, remove the old rusted line and lay it on the floor. Take the new tubing and using a bending tool, shape it the same as the original one. Next, slide the new fittings on the pipe at each end.
You will need to double flare the new line, so a double flaring tool is needed. However, most parts stores will lend one to you.
If you look at the pics below, they show how the procedure is done.
I'm only suggesting this type of tubing because of rust. I'm not sure where you are located, but if the original ones rusted, the new "steel" type won't last very long.
Take a look through the directions below and let me know if they help, if you have questions, or if there is anything I can do to help.
See pics below.
Images (Click to enlarge)
Wednesday, September 22nd, 2021 AT 6:09 PM