AC fuel pump date code research data

[Terry M.]

Re: AC fuel pump date code research data

Terry,

I just got an email from someone on the NastyZ28 forum who has a "LH40709" AC fuel pump from a 1970 Corvette LT1.
"LH" would be Dec. 1968 in my theoretical AC fuel pump date coding. Like I said before, I do not have all the answers, just passing on information.

Dave

Well I guess I will wait until I have the pump back in my hands and take another look.

[Mike E.]

Re: AC fuel pump date code research data

David:
Two head-scratchers to add to the list:
68 small block VERY original mechanically unmolested car, May 68 build: fuel pump is 197L40658
71 LT-1, 30k-mile LT-1: mid-July build: fuel pump is 38K40709
Also one that kinda fits the mold:
71 LT-1 late November 70 build: fuel pump is LH40709
Two different plants building pumps for AC? What does the 197L mean for the 68? And the 38K for the late 71?
Does there need to be two distinct theories for fuel pump dating in that vintage?
Regards,
Mike

[David L.]

Re: AC fuel pump date code research data

David:
Two head-scratchers to add to the list:
68 small block VERY original mechanically unmolested car, May 68 build: fuel pump is 197L40658
71 LT-1, 30k-mile LT-1: mid-July build: fuel pump is 38K40709
Also one that kinda fits the mold:
71 LT-1 late November 70 build: fuel pump is LH40709
Two different plants building pumps for AC? What does the 197L mean for the 68? And the 38K for the late 71?
Does there need to be two distinct theories for fuel pump dating in that vintage?
Regards,
Mike

Mike,

197L40658 = 197th day of 1972 on 68 Corvette
I doubt that a fuel pump will last 44 years but maybe it can. Does "VERY original mechanically" mean it definitely has the original fuel pump?

38K40709 = 38th day of 1971 on 1971 Corvette (mid-July 1971)
Seems about right.

LH40709 = Dec. 1968
This same pump seems to be on a few 1970 Corvettes as well.

I don't have all the answers. It really does not matter if fuel pumps are dated or not because it's not in the judging guides.

Dave

[Terry M.]

Re: AC fuel pump date code research data

Mike,

197L40658 = 197th day of 1972 on 68 Corvette
I doubt that a fuel pump will last 44 years but maybe it can. Does "VERY original mechanically" mean it definitely has the original fuel pump?

38K40709 = 38th day of 1971 on 1971 Corvette (mid-July 1971)
Seems about right.

LH40709 = Dec. 1968
This same pump seems to be on a few 1970 Corvettes as well.

I don't have all the answers. It really does not matter if fuel pumps are dated or not because it's not in the judging guides.

Dave

Yet Just kep pushing

[Ronald L.]

Re: AC fuel pump date code research data

It will matter to some to have the correct date just because. Looks like the key to the date codes is in the transition from 2 digit to three. Another year and more data and the detail can become clear. Dave have you looked at other pumps in this time period that mechanically could have run on this same line? Other than a few old dates on '70 Corvette's which could be explainable, the balance of manufacturing was running smoothly in Flint, Mi.

[Brian G.]

Re: AC fuel pump date code research data

Is your wife the original owner?

She bought the car from the original owner in April of '76. I've known the car since '77 and don't recall any fuel pump problems. But, my future Father-in-law was still the maintenance man for the car back then, and could have changed it without me knowing.

[David L.]

Re: AC fuel pump date code research data

Ron,

I rely on information from others who absolutely know that their fuel pump is original and there are very few owners who have their original fuel pump whether it's still on the car or in their collection of original parts. Statements like "very original mechanically" just do not cut it.

Here's another curve ball.
A NCRS member emailed me about a couple of fuel pumps stamped "0K 40709" and "1K40769". The "0K 40709" kind of baffled me so I did a little research on Ebay and found one particular seller who sells "remanufactured" AC fuel pumps who I have also seen at Spring and Fall Carlisle in years past.
Listed in his auctions are the following "remanufactured" fuel pumps:
"DE 40366"
"FG 40659"
"DJ 40731"
"0D 40768"
"0K 40709"
"1K 40482"

IMO, the first 3 fuel pumps are dated as follows:
"DE" = April 1965
"FG" = June 1967
"DJ" = April 1970

IMO, the last 3 fuel pumps must have a different date code format which I have never noticed and possibly could be as follows:
"0D" = 1970, April ???
"0K" = 1970, October ???
"1K" = 1971, October ???

Are there 3 different AC fuel pump date code formats???????????????????????
Is there more then one AC factory that made fuel pumps????????????????????

It's always easy to criticize but not that easy to come up with original ideas. Over the past 40 years in my business I have noticed that those who can not design end up working for city, state, and federal agencies strictly doing reviews.

Dave

[Ronald L.]

Re: AC fuel pump date code research data

Dave, just noticed that the master rebuilder now embraces via his sales of the date codes exist, good news.

On the question of different plants, not likely, different machining and asy lines within the plant for different styles and volumes of pumps.

[Larry M.]

Re: AC fuel pump date code research data

Dave, this is commenting on a very old post. I was reading a picture article online on how to rebuild a Pontiac AC fuel pump and the guy included the attached pic with the following legend:

5 A close up of the pump flange reveals the date-code (6550DE). Deciphered, the number 6550 is the GM short number for the part, D (April), and E (year, 1965).

I immediately thought of you and your research. This guy believes the same thing you do and states it as a fact. Thought you'd like to see this. Here is a link to the article if you want.

http://www.carsandparts.com/Articles/Classics/Tech/rebuilding-a-pontiac-fuel-pump-1

[Patrick B.]

Re: AC fuel pump date code research data

IMG_1018.jpgIMG_1019.jpgIMG_1020.jpgIMG_1021.jpg

Terry,

Yes, you did post your photo in another thread and it is STILL hard to read.
First of all the last digit on your fuel pump looks more like a "9".
My 1972 Corvette Parts Catalog lists GM # 6470110 (type 40709) for 69-72 Corvettes w/SHP 350 engines.
I don't think I have ever heard or seen an AC 40708 fuel pump.

In my study (the very 1st post) there are two 40709 pumps:
"LH40709" ("LH" = Dec. 1968) in a 1970 Corvette "V0114CTU" (Jan. 14, 1970)
"LH40709" ("LH" = Dec. 1968) in a 1970 Corvette "V0702CTK" (July 2, 1970).
It does seem odd that two 1970 Corvettes have the same pump with the same "LH40709" stamping made in December 1968. I wonder is AC rotated their fuel pump stock like the supermarkets so future Corvettes restorers would not be confused.

Have you ever looked at your "LN40708" pump with a good magnifying glass and good lighting?
It looks to me like it POSSIBLY could be "LH40709" but I could be wrong.

Dave

Dave: It looks like they stocked up for years of 40709 pumps in December 68. The first pump pictured below (assuming my attachments work right) is from my 70 LT-1 which is later in the year than Terry's (engine V0625CTK, car July 3). I thought it was EH until I saw the picture which looks more like LH. The second picture is a pump from a 69 350/300 Corvette built in July 1969. Both pumps have 68 casting dates- one with 7 lines and the other with 10 pin bumps.


The last pitcures are of a 40482 big block pump with a 1989 casting with 10 pin bumbs and the box it was sold in.

I see my pictures ended up at the top instead of the bottom of the page.

[Terry M.]

Re: AC fuel pump date code research data

Since David began posting of this date code I have found another LH40709 pump on a much later 1970 LT1 -- #14544.

BTW: Trtacking the pump date and the engine assembly date will be deceiving. The fuel pumps were installed at St Louis and a better representation of the timeline for assembly will be by either car SN or body build date.

[Michael J.]

Re: AC fuel pump date code research data

BTW: Trtacking the pump date and the engine assembly date will be deceiving. The fuel pumps were installed at St Louis and a better representation of the timeline for assembly will be by either car SN or body build date.

That's interesting Terry, I have heard of and seen some originals that were just a few days before the build date of the car. Guess that was a JIT item on some?

[Patrick B.]

Re: AC fuel pump date code research data

My LT-1 is #14297, just a day or earlier than the second one Terry observed. Are there any 40709 pumps that weren't manufactured in Dec 68?

[Bob W.]

Re: AC fuel pump date code research data

Dave, I found two pumps in my garage one ac crimped type stamped 23sk40658 the other rebuild able type with a tag stamped 40658

[Neal K.]

Re: AC fuel pump date code research data

Anyone have information on the application of a fuel pump stamped DF 40433. I am looking at a rebuilt one offered on eBay for my 67 L79.Sept. 1966 production.
Thanks
Neal