Fuel pump rebuild 1950 320

[Rod Frazier]

Anyone have a suggestion for removing the actuating arm pin so as to get the pump completely apart?  I have an original n.o.s. pump that I want to make ethanol resistant.  It looks like the original pin had a screwdriver slot on one side, but it's been boogered up....maybe what I actually have is a very old rebuild that was put back in the original box.  The pin that comes with the kit from Bob's is grooved on the ends for circlips but the original has washers,  (or maybe a shoulder on one side) which I guess means that there must be a small screw on one end and  the head on the other end must be a little larger diameter than the body of the pin. Anybody done one of these recently?

Edited January 3, 2018 by Rod Frazier
goof (see edit history)

[Bloo]

Is it anything like this 51? Apparently the 51 was riveted over a washer and needed it's head ground off to be removed. That would explain the new pin that takes snap rings, as the old one wouldn't be reusable without a bunch of work.

 

http://www.buicks.net/years/51/51_fuel_pump.html

 

I am having a little trouble visualizing where the screwdriver slot is. Do you have any pictures?

 

FWIW if that pin is riveted, I would try to verify that it is not worn, and if so, I would leave it alone.

[Rod Frazier]

Yes, I think it's basically the same pump, and probably I'll have to grind it off.  Thanks a million for the attachment.......I figured it be so simple I wouldn't need such a thing.....but obviously I wuz wrong!

[Rod Frazier]

O.K., guys, I'm getting desperate here!  I'm halfway through this rebuild but I absolutely CANNOT get the rocker arm link disconnected from the vacuum diaphragm.  With some trouble I got the fuel diaphragm disconnected by "wiggling" the rocker arm, but I bet I've spent an hour trying to get the vacuum diaphagm off without the slightest sign of success.  Any ideas?  Anyone been through this process?  (I'm already starting to worry about putting it all back together).

[DonMicheletti]

I made a "tool" of sorts out of a piece of 1/8" diameter welding rod that would reach in behind the arm and manipulate the tail of the diaphragm .

 

I used the same tool to reassemble it.

[Rod Frazier]

You wouldn't have a picture of it, would you?  I'm getting about ready to leave the whole thing on the kitchen table with some cookies in hopes the leprechauns will come in the night and finish it up for me!

[Bloo]

I hope I haven't lead you astray by suggesting you not take the pin out. I have rebuilt a bunch of fuel pumps, but never that exact one. I think I remember rebuilding some pump where the pin HAD to come out, but I don't think it was riveted. I am sort of confused because in the Hometown Buick link it looks like you would have to have the vacuum diaphragm off before you could get the other one. It must be different.

 

This part is always a pain in the ass on any pump. I imagine there is a spring trying to hold it hooked and centered, and you have to push it up and sideways at the same time, something it really, really doesn't want you to do. There is also the mechanism (slop) in the arm that allows the fuel diaphragm to not pump when fuel is not needed. I would love to see what Don made for a tool. That will probably be the next step. If you were close I would come over there and wiggle it out. You don't happen to be in central Washington State do you?

 

[DonMicheletti]

Unfortunately I do not have a photo of my "tool".

I think I just put a 90 degree bend at the end about 1/2" long and just fished around.

I was surprised at how well it worked both on disassembly and reassembly.

Like you I struggled for a long time before I got the idea of a tool. It was really crude. I think a chunk of coat hanger will work too.

 

The dual action pumps are a lot more difficult than the single action ones in my opinion.

[Rod Frazier]

Bloo:  To be honest, I took the pin out just because the manual said to, but.....who knows?.....maybe I didn't have to, although I think without the rod loose you'd have to move the diaphragm around enough to damage the seal.  The manual did  say to remove the vacuum diaphagm first, but offered no suggestion as to how, and the fuel diaphragm was not too hard to get free.  Don:  Don't worry about it ......I'll make one from a coat hanger and give it a try.  There's alway the 3 lb. hammer option