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Things have been going smoothly on the fuel pump rebuild until I started reassembling the fuel diaphragm. According to the diagram provided in my rebuild kit, there should be a spring on the diapragms rod. My pump did not have a spring. I believe the service manual mentions a spring as well. No listing in the parts manual diagrams for the fuel pump. Seems odd that my car ran fine without this spring. Anyone know what I should look for at the hardware store for a replacement? Maybe my pump is not supposed to have one?

If you're speaking of the spring that I'm thinking of, it's essential as it provides the pressure to drive the diaphram and discharge the fuel and thus it also established the fuel pressure. If so, you can probably forget the hardware store; try a professional rebuilder or buy a core to get the spring.

Good break-down pictures of double-action fuel pumps in old Motor's Manuals, Chiltons, AC catalogs, Packard shop manuals, some Packard owner's manuals, etc. Let me know if you want me to scan a post one for you.

Thanks for the offer Owen_Dyneto. I think the kit I got has pages scanned from one of those sources. They just sent paperwork to cover a variety of pump types. Below is the scan. My vacuum side is complete with the heavy spring (spring P) and the cone shaped spring (spring S) for the oil seal.

My pump delivered fuel without issue (at least from what I can tell), but according to the diagram, I am missing spring B. It must be a lightweight spring since you do not need to screw the halves back together with longer screws like the manual suggests for the vacuum side, because spring P is so strong.

I'm going to try calling Then and Now and see if they have the spring to sell. I wonder if it compresses similar to the cone spring (oil seal spring S). I could use my old one there since it fits (see pics below).

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The cone shaped spring is the right one for the fuel diaphragm.

Thanks BDeB...You are very versed in these pumps.

I know the cone shaped one was the right one for the vacuum side for the oil seal. So I can use my old oil seal cone shaped spring as the fuel diaphragm spring. Great news as I can continue to reassemble. Thanks for your help!

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Oops - I thought you meant that the cone shaped spring had come from the old fuel side.
The one from the seal on the vacuum side is probably not strong enough for the fuel diaphragm, so you will need to find a replacement.

No worries. I knew I wouldn't get off that easy. Then and Now has the correct spring and it is on it's way. I'm amazed that this car ran so well. When I rebuilt the carb, there was a part missing. Now the fuel pump is missing a spring. I wonder how it is going to run now that it has all the parts it is supposed to have!

9-29-11

Well I got the spring from Then and Now and it looks like the wrong one. I told them I need the fuel diaphragm spring and it looks like they sent the vacuum side. Pics below.

In the meantime, I reassembled the vacuum side of the pump. When reassembling the halves, I used two longer screws to pull the parts together while I had a screw driver in the arm hole to push up on the diaphragm (preloading it). It was very awkward, but I managed. Then the rest of the screws went in and the longer ones replaced with the correct size. Then I painted it silver. So far, it looks pretty good. I'll be happy when I can have the rest of it back together.

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Here is what the correct spring looks like compared to the vacuum side spring.
It is 1-7/8" long and 1" diameter.

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Thanks BDeB! That pic really helps. I didn't get a chance to call Then and Now today. I will probably e-mail them the pic of the spring you show so they know what I need.