tm9-801.com

It seems that the first thing to go is the diaphragm. Age and use simply wear them out (although some will say ethanol will eat NOS diaphragms, I have yet to see any sort of proof, and the two NOS kits I have installed are going fine 4 years into service).

Basically every other type of vehicle restorer is simple replacing the diaphragm material. There is no rocket science to it. Use a quality rubber (one guy is using a patch from an old inner tube).

Here are some links to the oh-so obvious:

http://www.vintagewerks.com/Fuel%20Pump ... ation.html

Here's the post about a guy using a tire (read to the bottom)
http://forums.aaca.org/f120/source-diap ... 67208.html

Here's a company that is selling AC rebuild kits for $60.. look at the diaphragm... nothing a steel rule die won't do... or a sharp knife and a .30 cal empty cartridge (that's a tip from AM).

http://www.maritimedragracing.com/antiq ... cellar.htm

There is nothing magical about how an AC fuel pump's mechanical diaphragm works. Its really just a piece of rubber.

Using material from an old inner tube for a diaphragm in a vacuum pump may work fine but i would certainly not use it for a fuel pump. It's very unlikely that it would be fuel proof and could result in engine destruction if the pump is of the type that doesn't have a pull rod seal to keep fuel from getting into the oil pan if the diaphragm fails.
I wrecked a 216 Chev engine by installing a NOS fuel pump that turned out to have the diaphragm turned porous with age.
David

Fuel in the oil is pretty easy to spot. I have gotten into the habit of checking oil before every trip in the jeep.

Rubber would most likely split and not hold the vacuum required to suck fuel from the tank.. so not much would get into the crankcase (the pump is slightly higher than the filter, and much higher than the in tank pickup on CCKWs.

Nitrile is the best substitute. Would handle gas and ethanol fuels.