1969 SB Fuel Pump question

[Thomas C.]

I just rejoined after a 15-year break....it's good to be back with access to all the information. I searched the archives, and if after reading this question, someone wants to point me to already posted article/thread, I'm happy to do some reading.

I realized that my car didn't have an external fuel filter, so I ordered one along with the prebent hoses. After looking, I figured someone had put on an aftermarket pump, but when I pulled the fuel pump today (my car is a September 69 build-date car), it had an AC-stamped 40769 fuel pump. It might be hard to see in the picture(s), but as best I can tell, it appears that the full stamp reads 140I40769 which all my research says is a 140 julian day, 1969 fuel pump build date. That would line up nicely with my car's build date, however, I can't find any other 1969 SB cars that used the 40769 before 1970. I believe I'm supposed to have a 40658 pump possibly with an FI or GI preceding it on the stamp. Can anyone confirm that the 40769 wasn't used at all on a 1969 SB?

Thanks in advance.

Tom

Fuel Pump Picture.jpgFuel Pump Picture 2.jpg

[Ron G.]

Re: 1969 SB Fuel Pump question

Thomas - After reviewing the 68-69 JM, it is indicative of your car's application having a 40658 even though the date code on it corresponds with the vehicle. Could it be that it may have been replaced when the car was under the factory warranty.

[Thomas C.]

Re: 1969 SB Fuel Pump question

I guess it's possible, but it seems odd that they would have replaced the pump and lines, and removed the filter, since that is what it would have taken to move to the larger-canister fuel pump. They could have updated it to the 1970 and later set up, but what are the chances that they could have randomly chosen a pump that aligns so closely with my car. I'm slow to want to replace it if it's correct. So far, I've not found too many parts on my car that aren't the correct original.

Tom

[Patrick H.]

Re: 1969 SB Fuel Pump question

We have found other 40769s made in 1969, so it would not surprise me.
What month was your car built?

[Thomas C.]

Re: 1969 SB Fuel Pump question

I thought it was September, but my quick search says it came off the line on October 22nd.

Tom

[Joe L.]

Re: 1969 SB Fuel Pump question

I just rejoined after a 15-year break....it's good to be back with access to all the information. I searched the archives, and if after reading this question, someone wants to point me to already posted article/thread, I'm happy to do some reading.

I realized that my car didn't have an external fuel filter, so I ordered one along with the prebent hoses. After looking, I figured someone had put on an aftermarket pump, but when I pulled the fuel pump today (my car is a September 69 build-date car), it had an AC-stamped 40769 fuel pump. It might be hard to see in the picture(s), but as best I can tell, it appears that the full stamp reads 140I40769 which all my research says is a 140 julian day, 1969 fuel pump build date. That would line up nicely with my car's build date, however, I can't find any other 1969 SB cars that used the 40769 before 1970. I believe I'm supposed to have a 40658 pump possibly with an FI or GI preceding it on the stamp. Can anyone confirm that the 40769 wasn't used at all on a 1969 SB?

Thanks in advance.

Tom

[ATTACH=CONFIG]100564[/ATTACH][ATTACH=CONFIG]100565[/ATTACH]

Tom------


I suppose it's remotely possible but I've never heard of it. I am the original owner of a 1969 small block which was built in mid-September, 1969. It originally had an AC 40658 fuel pump. Like all 1968-69 Corvettes I know of with Q-Jet carb it also had a GF-432 in-line fuel filter between the fuel pump and carburetor. This filter had provisions for a fuel return line to the fuel tank.

With the AC 40769 fuel pump, which has it's own provisions for a fuel return, I suppose the fuel return functionality was transferred from the filter to the pump. As I say, I've never heard of this before for a 1969 but I suppose it's possible.

One thing I'm curious about, though, is this: the 1968-69 configuration had the fuel filter mounted with a clamp to the AIR pump bracket. The fuel line was thus 2 piece----one length from the the pump to the filter and another from the filter to the carburetor. The 1970 configuration which used no filter had a 1 piece line from the pump to the carb. However, the 1970 configuration for Q-Jet carbs was designed for engines without an AIR pump. So, if a 1970 style pump (i.e. the 40769) was used for 1969, what fuel line was used from the pump to the carb? I don't think the 1970 fuel line would have cleared the AIR pump and bracket.

By the way, I'm also very surprised that you have a fuel pump that's lasted for 50+ years.

[Thomas C.]

Re: 1969 SB Fuel Pump question

Hi Joe. Thanks for the reply. My fuel line was/is a one-piece line that went from the pump to the carburetor. AIR pump and bracket were missing when I purchased it in 96, so I'm unsure how the 1-piece fuel line would have navigated that. Great point.

There is a gold, small block, Dec 69 build-date car on ebay for sale that appears to be quite correct and has the filter assembly on it. Although the filter to carb line looks a bit wonky in my opinion.

I'm leaning towards going back with the 40658-style pump and accompanying lines, and hanging onto the 40769 pump and possibly have it rebuilt just in case differing data comes up in the future. Is there a NOS pump available that most closely resembles a 40658 that I should try to obtain? I have access to a NOS 41180 pump that has the correct AC stamp, and the only difference I can see is that the supply line nipple is not pointing in the correct direction, but other than that, it appears to be identical to a 40658.

Thanks to everyone for helping me navigate this.

Tom

[Terry M.]

Re: 1969 SB Fuel Pump question

I thought it was September, but my quick search says it came off the line on October 22nd.

Tom

Don't change your car to match the judging manual when, as in this case, all the evidance points to the part (fuel pump in this case) being original. We always have more to learn about these cars. Hang in there and given enough time we will learn all there is to learn. That will be long after I have passed, and maybe y'all too.

[Thomas C.]

Re: 1969 SB Fuel Pump question

Terry,

I don't disagree with what you're saying. I'd be less inclined to change it if someone would have weighed in and said it's possible that the pump is original to my car, but everyone seems to be in agreement that if it is original to my car, it'd be a rare case that would need explained (me paraphrasing). Joe makes a good point with regard to the AIR pump bracket as well.

I'm slow to throw the baby out with the bath water, and that is why I'll keep the pump and fuel line just in case I learn that it could have been factory equipment. I love originality and I'm even trying to get the correct bolts with the correct markings when I make an update to my car. We sure could use more small shops that rebuild our original equipment in order to keep our cars as original as possible, because you're right, once we're gone, they'll still be more to learn, and less first-hand knowledge available, and the more changes to our cars we make, the less the future has to go on.

Tom

[Joe L.]

Re: 1969 SB Fuel Pump question

Hi Joe. Thanks for the reply. My fuel line was/is a one-piece line that went from the pump to the carburetor. AIR pump and bracket were missing when I purchased it in 96, so I'm unsure how the 1-piece fuel line would have navigated that. Great point.

There is a gold, small block, Dec 69 build-date car on ebay for sale that appears to be quite correct and has the filter assembly on it. Although the filter to carb line looks a bit wonky in my opinion.

I'm leaning towards going back with the 40658-style pump and accompanying lines, and hanging onto the 40769 pump and possibly have it rebuilt just in case differing data comes up in the future. Is there a NOS pump available that most closely resembles a 40658 that I should try to obtain? I have access to a NOS 41180 pump that has the correct AC stamp, and the only difference I can see is that the supply line nipple is not pointing in the correct direction, but other than that, it appears to be identical to a 40658.

Thanks to everyone for helping me navigate this.

Tom

Tom-------


Something I'd be VERY interested in: try installing an AIR pump and support bracket. Then, see if the pump-to-carb fuel line will "work" with the pump and bracket installed. If it won't, then the pump and fuel line are NOT original to the car because there is absolutely no way that any 1969's were ever built without the AIR system.

[Thomas C.]

Re: 1969 SB Fuel Pump question

Joe,

I'd be interested in that too, however, I do not have an AIR pump or support bracket to check that theory.

Tom

[Joe L.]

Re: 1969 SB Fuel Pump question

Joe,

I'd be interested in that too, however, I do not have an AIR pump or support bracket to check that theory.

Tom

Tom------


Maybe you could borrow one from someone living close-by? The bracket and pump are very easily installed and removed----not more than about 10 minutes work.

[Thomas C.]

Re: 1969 SB Fuel Pump question

Joe,

Ask and ye shall receive. I bought a smog bracket to see if it would work. I didn't go as far as buying a pump...maybe you have an extra you'd be willing to part with. :-) Here is a picture. Ignore the fact that my valve covers are on the wrong side....something else I need to address.

Tom

fuel line with smog bracket.jpg

[Joe L.]

Re: 1969 SB Fuel Pump question

Joe,

Ask and ye shall receive. I bought a smog bracket to see if it would work. I didn't go as far as buying a pump...maybe you have an extra you'd be willing to part with. :-) Here is a picture. Ignore the fact that my valve covers are on the wrong side....something else I need to address.

Tom

[ATTACH=CONFIG]100820[/ATTACH]

Tom-------


That could be the 1970 style fuel line. I don't recall that the 1970 style line was in such proximity to the valve cover but it may have been. Does the rest of the pump-to-carb fuel line look like the line labeled "M" in Dr. Rebuild's drawing?

http://www.docrebuild.com/dr-r-web/GAS-LINE2.pdf

[Thomas C.]

Re: 1969 SB Fuel Pump question

Joe,

From looking at label M, it appears to be nearly exact. Here's a picture with the fuel line configured as Dr. Rebuild has it in his drawing so you can see what you think.

Tom

fuel line.jpg