I have heard that the fuel pumps going onto our Cadillacs are not lasting. Has anyone taken theirs apart to see what they find wrong. I had to change the fuel pumpp on my 63 Sedan, and the pump was not that old. I took the pump apart, and found one of the valves had come loose, as it was not staked in place. I had a rebuild kit, and the instructions state to stake it in place. Even the service manual sais to stake the new valves in, when rebuilding a pump. The new pump that failed, did not have the valves staked in place.
So if you have a bad fuel pump, take the bottom off, and see if there is a loose valve.
I may add these to my rebuilt items list.