F12 Fuel pump

Got a Question.. on my 37 F12, I rebuilt the pump. Pretty sure I got it back together rite but it seems WAY to tight. Was wondering if there was a schematic of The AC pump anywhere so I can check if i got it together rite?

You are joking RIGHT? I have never been around an F12, but my old F20 was gravity fed to the carb, and I suspect that the F12 was simular!

All the 12 series tractors had fuel pumps, IHC goofed, they did not allow enough space between the push-rods to allow the spark plugs to be put on the right-hand side of the engine. (The early Farmall A had hardly enough room until they changed the head so that you could get a normal plug spanner on the plug). As a result the spark plugs are on the left side of the engine, under the manifold (great if you need to access the plug on a hot engine). As a result an updraft carburetor as used on other IHC tractors was not possible so instead they used a downdraft carburetor which was too high on the engine for gravity feed from the tank, hence a fuel pump to get the gasoline/kerosene/distillate to the carburetor. On a straight gasoline tractor not good news if the tractor has not been used for while, the fuel in the carburetor has evaporated and you can crank for quite some time before there is enough fuel in the carburetor to start. Just did for my O-12 today, took about 15 minutes cranking before it would fire up. The kerosene/distillate O-12 or W-12 and later F-14 tractors with the starting tank in the hood were easier as they had gravity feed for starting. The earlier F-12 with the starting tank in the back of the main tank had the same difficulties as the straight gasoline tractors. There is only about a 1/2 inch head on the T junction between the carburetor pipe and the return to the tank. Most of the fuel from the pump goes straight back to the tank!

That's perfectly correct. The F-12/F14 does not have a gravity feed to the carb but has a pump set low down on the block on the left hand side as shown in the pic.

thats a for sure. when the float bowl is full the fuel is directed back to tank. these little engines will run for about an hr. on a quart of gas so with fuel pump pumping steady the extra is routed to tank.the carb float bowl is full with only about 3 pump strokes. just like a diesel engine return from injectors is routed to tank.

It looks like an old man, can still learn something old every day!

So is it normal for those pumps to be tight after you rebuild it? I am worried about stripping the mounting bolts out when putting it back on the block.

I did not have to rebuild my pump, I had the pump off so the engine could be rebuilt. They had to hot-tank the engine 3 times to get the old cylinder sleeves out. Found new F-12 sleeves in original box and had crankshaft ground and new bearings at the same time. The T junction from the pump in front of the tank, one side goes to carburetor and the other side to the tank. There is about 1/2 inch up-stand inside the tank so not too much head to feed the carburetor. The original F-12 kerosene/distillate tractors had a very small header tank sticking up through the hood in front of the fuel tank, the overflow from this header tank wentt back to the fuel pump feed line.

You should be able to pump it by hand with a screwdriver with the pump in a vise.