help with fuel line, 1972 bavaria

i have traced the gas odor in the car to the fuel line coming off the gas tank. Its faint, but present when I get my nose up on it. There doesn't seem to be a leak, but I think the old line has cracks and its evaporating.
So its clearly time to change the line(s)!!!

I have a repair manual, but it doesn't show how to switch out the lines.
Does anyone know of a step by step?
The lines under the hood were replaced recently, so I think I may just be dealing with the ones in the trunk and under the car. Perhaps just the trunk one.
Do I really need to drain the gas tank before switching the line?

Help is greatly appreciated!

I never replaced the lines in the rear of my Bavaria, but I did go through two gas tanks. The first one was replaced in 1981 and the second one around 1990. You might want to unscrew the access panel to the gas tank on the right side of the trunk and see if you have any leakage around the seams of the gas tank. Mine leaked both times along the seam in the tank, and it was evident by inspection.

Sorry I don't have any helpful ideas on the lines themselves.

Chuck

thanks for the response, i checked the tank. It looks newer, and doesn't have any rust.
I was following my nose, the leak is defintely coming off that line. What I'm not sure about is the procedure to replace the tank line(s).

I found out a bit of information, which might help someone else:

1. The old braided hoses (and perhaps the current imported ones?) can not handle the ethanol in our US fuel, and they break down.
Therefore, my leak is not necessarily from a given crack but probably the entire hose is now corroded to the point the vapors are coming through it. I am going to replace it with Domestic high pressure hose and clamp it. Should be fine.

2. If you want to view schematics and get exact part numbers (and some measurements), go to RealOEM.com and look up your car. I located the drawing for my problem, and it helped me visualize the repair. I was able to confirm that after the visible grommet which the hose passes into, its a hard pipe.

http://www.realoem.com/bmw/showparts...05&hg=16&fg=05