1936 mechanical fuel pump
 

I have rebuilt a 36 fuel pump. The eye on the diaphram is not perpendicular to the pump arm. The holes on also did not line up on such diaphram. put back but does not seem to draw fuel. I saw on older post to try "twisting " the diaphram by putting in a vice, thereby removing any friction on the arm to side of the eye. Is it correct to assume I put the eye of the diaphram in the vise and twist the round steel section to get the position correct? Would it also mean that the eye is in some way threaded to the metal plate and that holds the rubber diaphram sort of like a sandwhich? Easy enough to try, just want to avoid ruining the diaphram.

Re: 1936 mechanical fuel pump
 

i hear ya...

between a rebuild kit with missing gaskets and diaphragm's with fixing holes in the wrong places (i suspect it was mislabeled and was for a slightly different pump) i bought a repop pump with a pushrod swivel that didn't swivel...and leaked. i bought a second (different manufacturer) fuel pump that so far has worked properly. the only good thing is that i now have a glass sediment bowl that at least let's me see if i'm getting fuel from the tank to the pump.

and BTW, i considered but then abandoned the idea of drilling new fixing holes for the diaphragm. as far as the swivel thing on the pump lever problem, i think i eventually just pulled it off as it looked like it might not be necessary, but that was on the first pump that i eventually abandoned because it leaked and so can't say whether or not the swivel connector is necessary or not.

Re: 1936 mechanical fuel pump
 

It's definately the correct parts. All were identical to the original. Somewhere on this post someone pointed out that almost all the kits were slightly off and I believe 3rd Generation sugested twisting them in a vise as that is what they did.

Re: 1936 mechanical fuel pump
 

I also have found the eye to be slightly out of position (or all the holes slightly off correct position) but installed it as close as possible without trying to adjust. Have not had a problem. Usual problems are the gasket for the top cover and the top cover bolt gasket leaking.

Re: 1936 mechanical fuel pump
 

This sounds like yet another example of “modern times” crappy repops. It’s been a while since I rebuilt any pumps, but I don’t recall any such issues with the older kits. It makes no sense to go into production with unusable junk.

Re: 1936 mechanical fuel pump
 

I rebuilt the fuel pump on my 53 in the last few years and used a kit from Then and Now Automotive. I had no issues with the diaphragm alignment to either the body or arm. I also put together a pump for the 38 in the last few years using one of their kits, again with no issues (well, no issues with the kit; I did end up taking apart 6 fuel pumps before getting enough good parts to make one functional pump).


I do remember having the diaphragm problem over a decade ago on the pump for the 37 sedan, but I don't remember who I bought that kit from.

Re: 1936 mechanical fuel pump
 

when I took the fuel pump off, there were to little washers in the cup of the arm held in by grease.
After not getting good vacuumn i put those back in the arm cup and voila, I had vacuumn and the pump is working!!
Must have been an old timer repair without replacing fuel rod.

Re: 1936 mechanical fuel pump
 

Rocker arm pivot wear has always been the weak point of those pumps. They’ve been farmer repaired with a spot of shoe leather, and there was also a cup insert sold to compensate for the wear. I forgot the name of the company, they made a bunch of different make-do products.

Re: 1936 mechanical fuel pump
 

I have two pumps for my 51. One made in Canada came with the car and the holes are symmetrical to the centerline of the pump. The other is a made in USA pump given to me by a friend. That pump has the holes offset from the centerline of the pump. I have diaphragms with holes offset to the rod and diaphragms that have holes centered on the rod. I never gotten an answer as to this issue but at least I am covered for whatever diaphragm arrives in a rebuild kit. I have found the pump will still work if the offset isn't too much.