In the past, on the Italian after market fuel pumps that are held together with a bunch of screws, I have prolonged their service life by disassembling them to paste grind flat the two mating surfaces. Being made of a cheap mystery metal they warp from over torquing the mounting bolts and heat from the engine. If the diaphragm is still pliable and not damaged, another six months of life can be had. The test for repair effectiveness is to put your finger over the input spigot while activating the pump arm. The stronger the vacuum, the better.
These pumps also have other problems rendering them more of a bother than they're worth. The pump arm fulcrum pin will wallow out one side from the effects of vibration and heat. The repair here is to fabricate another longer pin from a bolt or stud with holes drilled in each end to fit a cotter pin. Then there is the oil seal inside the pump body deteriorating from heat that allows crankcase oil/vapors to exit thru the vent hole on the pump body. I never could find a suitable replacement for this seal and the factory never responded to my queries.
On the factory pumps, the diaphragm and body halves are crimped together and not serviceable.
These are some of the reasons for my almost religious conversion to electric pump power. Can I get a rousing 'Amen' from the choir to my left?
Mildred Hargis