Unusual 40083 Fuel Pump

[Larry M.]

I bought a complete used pump on ebay which is an anomaly versus what I've seen or had before. It is from a low miles or early take off based on the condition and has some unusual features.

1. The stamped part is 40083 consistent with original assembly line versions (no date code letter after the number as seen on service replacements).

2. But the lower flange does not have the two "reinforcement" bosses which are typical of original assembly line pumps. So it matches a service replacement lower body.

3. The action arm cross pin has the cross or X on the head as typical for both assembly and service pumps but the opposite end which is normally spread by three "chisel" cuts at about 120 degrees is not cut. It is simply mashed by a press.

I have owned several of these pumps and have studied them. In my opinion this one has never been rebuilt. So my purpose here is simply to document it for reference by others. It is possible that an assembly top and service bottom have been put together but the compressed end on the cross pin is unusual or unique. The upper diaphragm and lower gasket and original 1960's style and appearance.

[Alan D.]

Re: Unusual 40083 Fuel Pump

Does it have the yellow lines on the diaphragm? What numbers are on the inside?
Any pictures?

[Larry M.]

Re: Unusual 40083 Fuel Pump

Alan - here are three of 14 pics I have from the ebay listing which I think illustrate the key points I've made, the part number, the cross pin, and the lack of lower bosses. Another pic shows the arm return spring which has significant yellow paint on it. The arm does not operate as I would expect so there is likely an internal failure. Likely an early failure and removal resulting in strong cosmetic condition. I'm pretty sure it has not been rebuilt although one lower cover screw does show some slot damage. I have not inspected it for dates.

[Alan D.]

Re: Unusual 40083 Fuel Pump

OK, not sure of "2. But the lower flange does not have the two "reinforcement" bosses which are typical of original assembly line pumps"
Not sure where these are located? Could you educate me a little more, pic is an original one.

[Larry M.]

Re: Unusual 40083 Fuel Pump

OK....so here are two pics of an NOS version of the assembly line configuration. These bosses which cover the 'IN' of "MADE IN U.S.A.' are visible. I have not seen a "40083" only version that did not have them until the one I just bought. I spoke with Don Hooper this morning and he has these on his original pump but doe not on a service pump he owns with the alpha date code stamped next to the 40083. I have several of these pumps which have the bosses.

Also, I looked at dates: the only ones in the lever arm cavity would be visible and there are none but the part number is there.

[Alan D.]

Re: Unusual 40083 Fuel Pump

Here are two original pumps, showing the date codes on the inside. The 64 pump I took off in Aug of 1967, the original owner (in same state as me) does not recall replacing it. So these both have the "reinforcement" bosses as one expects however it would be nice to know if the yellow lines were used on rebuilds/NOS ??

[Larry M.]

The "unusual" pump which I posted about has shown up again. A guy on ebay listed an NOS which other than being unused is a duplicate of the one I have. It sold this morning with an asking price of $1000. I don't know what he got on an offer. There had to be more of this version if two showed up in 18 months.

The "assembly line version" which Alan and I have posted pics of is well documented on this forum. Also well documented is the service pump with date code letters adjacent the 40083 and without the bosses.

It would be interesting to know where the "unususal" version fits in.

The only other odd ball I'm aware of is the use of the die cast bottom cover with the "AC" logo on it. Sellers on ebay say this is the true original but I've not seen anyone on this forum confirm this.

[Gary B.]

Larry,

Wasn’t the domed, cast pulsator cover with the AC embossing used on the 1964 version of the 40083 pump? And the stamped steel, double hump cover came along after that?

Gary

[Larry M.]

That would be the logical guess but it would not have been all of 64. Alan Drake has certified the metal cover on a 64.

[Gary B.]

Larry,

I can’t verify the exact timing, but I’ve read several statements in the archives by some well known names who have stated that the cast dome cover with the embossed AC preceded the stamped steel cover. Or maybe there was an overlap period when both styles existed. Pre-‘66 is not my general area of interest or expertise.

Gary

[Alan D.]

Larry/Gary
The early 64's used the die cast bottom cover with the "AC" logo on it. I believe that from talks with older members who built engines. In fact they believed at the time mine was wrong, but later discussions confirmed the stamped steel cover was original, too. Believe my pump is original, since I was having stalling problems in 1967, replaced pump and stored in coffee can for 35+ years before rebuilding. Original owner never mentioned he replaced the pump either. So at present believe both covers are valid.

[Larry M.]

Alan, when was your car built?

[Alan D.]

Larry,
Late March 64