Anyone have the part number for a fuel pump on a 1935 207 cid engine? I think I found it online and it even came up at my local Napa store as a fuel pump, but the wasn't a photo of the top side of it where the fuel bowl sit. it looks like the one on my engine, but I want to confirm.
Roman, The common generic number for the fuel pump is 421. I didn't look but this number usually comes from being the last 3 digits of the longer Chevrolet number. I looked back at your photos and it looks like your grain truck has the correct fuel pump for a '35 or '36 engine. These are commonly available on eBay. It is likely that a modern diaphragm would be all that is needed to make that pump work for you. This diaphragm is available from JimCarter Truck Parts and perhaps from other vendors. I am not aware of this pump, in modern form, being available through everyday local parts sources. The 429 pump might be a regular stock item, locally. It fits the 216 engine starting in 1937 and goes forward for several years. I have seen this pump used on 207 engines, but the mounting surface and bolt spacing is different.
Mike is right. The generic number is 421. My 29-54 Master Parts book says the actual part number was #1523421 at that time. It also says the number 1521812 may be stamped on the flange.
The parts number that I was working from was in fact 1523429 which looks very much like the one on my green dump truck with the fuel bowl sitting on top of the pump, but from what you are saying, I need to be looking at the the fuel pump on my white grain truck to place on my green dump truck, correct?
I think the answer is yes. You are looking for the same pump as is on the white grain truck as per Mike above. It will have the filter on the side at the inlet as per Gene above. And I believe that filter will be cast on at a slight angle out away from the engine as on your grain truck... and not straight back as on earlier engines such as in 1929.
The '35/36 pump has the bowl hanging down. It angles out slightly from the engine. There are at least two versions, possibly more, of genuine AC/GM pumps with cast domes, screw on domes, single domes, dual domes. There might be dozens of casting variations among aftermarket pumps of the period. The mounting surface is smaller than the later pumps, but with a similar shape. Gene is correct about the shape of the arm in the 429 pump, but they apparently work on the 207 because I have seen them being used. My '36 truck had a 429 pump when I bought the truck. It was not working at that time but I have every reason to believe that it had worked. previously. From what I can see in the photo of the engine in your grain truck, the pump appears to be correct for a '35/'36 Chevy. Rebuild kits are available for a reasonable price. I believe the '34 pump has the same mounting pad and lever as the '35/'36 pump, but looks different, in some respect. functionally they would interchange, if I remember right.
Sounds like you have it figured out. Attaching a photo of a 421 on the left and a 429 on the right if someone down the line is wondering what they look like.
Well, I finally received my rebuilt carb a week ago and my first attempt to start my truck was underway, but unfortunately my fuel pump had a different idea. I bought an "old stock" OEM fuel pump weeks back, but it started to leak after a few cranks fo the engine. I checked the lines again and nothing is restricting fuel flow. I opened her up to take a look and although I didn't break it down completely everything looked in order with the diaphragm seeming in good shape. I put the pump back together and gave it another try today. The pump is pushing fuel to the carb, but it's still leaking.....see photos. I see a little fuel around the screws, but it seems to be more on the bottom of the pump which you can see in the photos. Fuel is puddling up on top of the engine block lip above the oil pan. There are vent holes on the bottom, so could it be leaking from there due to pin holes in the diaphragm. I just can't tell where the fuel is coming from on the pump.
I have another AC421 pump that was originally on one of my 2 trucks and I just received a rebuilding kit(tough to find in stock) for it this weekend. I am thinking of rebuilding one of the 2 I have and trying that out.
I think you are on the right track with the rebuild kit.
Some old diaphragms, probably most of them will not work with modern fuel. I recall helping a friend revive a 30s Buick a few years ago that had been sitting indoors since about 1952. It didn't take long at all before the fuel pump started leaking badly. I tore it down and discovered that the diaphragm was just several layers of cloth that had been doped with something, probably shellac-based. There was no sign of the doping except where the edge of the diaphragm had been clamped between the case halves. The cloth had been washed completely clean and the gas was flowing right through it. Alcohol is the solvent for shellac. There are many types of rubber that cannot stand alcohol either. In my opinion all NOS/NORS fuel pumps need a new diaphragm.
The diaphragm that is commonly sold for these pumps is one that is made for V8 Fords of the same era. They are the same except that the holes might need to be altered a little to orient the diaphragm properly. Jim Carter sells this part. Others may have it also.
I found the kit at "Filling Station" although I wish I could just find someone that just offered the diaphragm. The old "new stock" is in great shape and only needs a new diaphragm.
I here are a few thoughts as you move eased with this project.
I wonder if it is false economy to just replace the diaphragm. My experience is that these classic cars sit a lot so there is plenty of time for gasoline to evaporate and leave a film or gum on everything, especially the check valves.
I looked at your pictures again. That gasoline you see leaking could also be from around the pivot pin for the lever arm. I assume that is gasoline and not oil.
The problem is that the pin is harder that the die-cast pump housing. When new the pin is a pretty snug fit in the housing and a slightly looser fit in the hole in the arm. So the arm pivots on the pin. Due to load on the arm over time the pin will “push” against the housing and deform the hole. Then the pin is loose in the body and sometimes rotates in that hole. So you might need to have a brass busing inserted if the hole is too worn. If the holes in the pump body and arm are too worn that will reduce the stroke of the diaphragm and fuel delivery.
Isn't the pivot pin on the engine oil side of the things? If there is gasoline (and not oil) leaking from around the pin, I think you better be looking for gasoline in the crank case?
Thanks for helping clarify my post. You will not have gasoline leaking where he shows unless the diaphragm is leaking. If things are correct the pin is only exposed to oil.
This is an area where you can get either gas or oil leaking. Or maybe even both!
There is some oil splash that comes from the rotation of the lobe on the cam as it rubs against the pump arm. It's not a lot of oil but you will notice it in that area when you remove the pump from the block.
I agree that if the diaphragm is leaking you will get gasoline flowing into the lower section of the pump and into the crankcase. If the pump body does not a vent hole like rustydawg describes and the pin is snug in the pump body you will probably not even notice the gas leak. As you noted the real clue will be a higher than expected oil level or a gasoline smell when you check the dipstick.
I didn't check the oil today for gas when I went to install the fuel pump. The fuel pump that was leaking was a new old stock I bought, because there were no rebuild kits at the time and I was antsy to get the engine running....bad trait. I took the old fuel pump I removed months ago and rebuilt it last night. Although I have another issue to resolve now after trying to start the engine, leaking fuel was not one of them now.
I will reach out to you Mike, so that you can guide me on where to find just the diaphragm for the new old stock pump now sitting on my bench.
I think you can get it from Jim Carter Truck parts. If not. Try the Ford vendors. Call me if you have trouble.
Mike 573 8964 6539
I found a complete kit at Dennis Carpenter for a Ford V8 33-47 at half the cost. This kit even includes the large internal spring. Who knows if it will work on the 421 though. Photos of parts look identical, but one can never tell by just a photo. Might give it a try and see.
It is interesting to me that the diaphragm for the AC 405 (29-33) does not work in the 421. They both use the same top cover. My guess is the diaphragm pull rod on the 421 is swaged/riveted to the diaphragm and is not serviceable like the 405 which bolts together. I would be interested to see what you find once you open them up. The aftermarket pump you pictured may have a pull rod you can take apart?
We have ground off the crimp, drilled the rod for a small screw, installed the diaphragm for the '29-'33, used red locktite to retain the screw for the later fuel pumps. Just be sure to properly align the diaphragm holes and the slot in the rod. Has worked well so far.
