I took my 65 Malubu SS 327 out of storage recently only to find a leak at the connection between the fuel pump and the line up to the carburetor. Same thing happened last year, but I was able to tighten the coupler to fix it. This time it did not work. I noticed the teflon tape to seal the threads is peeling off.

Has this happened to ayone, and what do you recommend?

Have not had any personal experience with that fuel pump specifically...but what threads are you using teflon on? Teflon is for sealing pipe threads only. If you are using it on the threads of a flare or compression fitting, it can lead to a leak.

I have also seen certain compression fittings cause leaks in aluminum pipe because it is so soft.

Do any of these conditions apply?

It seems to be standard thread. I noticed some on there as I adjusted the fitting. Has anyone used Teflon tape to seal threads on their car?

The tape is not recommended for fuel fittings or lines as pieces can flake off and clog things up. You should NEVER use anything on a flare nut (the nut that spins on the fuel line) and can use a teflon paste or Permatex #2 if you absolutely must, on pipe threads. Pipe threads used in automotive applications are a 'tapered thread' type which means the farther in you tighten them, the more interference they cause. In other words, self sealing. If your fuel pump uses a NPT {pipe thread) fitting, you have to be careful NOT to overtighten and crack the casting. After all there is NO pressure on the input and only 7 or 8 psi on the output.