Fuel Issue J.D. 300 Indust.

Recently rebuilt the fuel pump on J.D. 300 Industrial 1969 version. Old pump had bad diaphram and fuel would seep into the block. When I start the engine the fuel pours into the bowl just to the point where is spills into the inner "core" but after about 10 minutes it runs out of fuel. The rebuild kit came with two diaphrams/disks and I thought I put them into the correct sequence... any suggestions? Thank you.

If it is the upright sediment bowl I'm thinking of, it WON'T fill with fuel, there will always be an air pocket at the top.

It's hard to explain why it would pump during cranking and startup, and then quite after 10 minutes!

Is this a gas or a diesel... if a gasser, it MAY have ignition problems (thermal coil or condenser) that cause loss of spark after 10 minutes, or if a diesel, you may have the famous "clear plastic governor ring turns black and disintegrates into 'coffee grounds'" that plug the fuel return system, causing fuel delivery to stop, and stalling the engine.

Any chance one of those issues is going on and you are blaming the lift pump?

Whatever the problem is - it ought to be self-evident (yeah, I know -famous last words).

All there is . . . is a diaphram and two one-way check valves. If the diaphram is in one piece and moves back and forth -and the check valves are facing the right way and opening and closing - it has to work assuming the arm is riding up and down on the camshaft.

I'm surprised you found a kit. How much was it? You can find a brand new French Sofabex fuel pump that is a "take-apart" type and built better then the original AC pump. Usually costs around $40 new.

Here is info on the Saran-France Sofabex pump. They sell it here for $41. Deere used it OEM on many tractors although it's not always easy to find in Deere literature.

Replacement fuel transfer pump, can be repaired. For diesel tractors: 1020, 1520, 2020, 2030, 2040, 2240, 2440, 2510, 2520, 2630, 2640, 2750, 2950, 2955, 3020, 3150, 3155, 4000, 4020, 4030, 4050(6359TP), 5020, 6030. Can be serviced with repair kit TP-RE42.
Part No: TP-RE42211B

Thanks for the fast replies... I think I paid about $45 for the rebuild kit and it came with the new diaphram, and the little disks and yeah, I know it seems easy but I have had this thing apart probably a dozen times using every combination. I'm sure its a fuel issue not an ignition problem. When it's running, and the fuel is flowing it's hitting strong on all 3... when it quits the fuel (Gas) falls below the "spillway". Could the cam be worn and its not giving enough of a lift to the pump? This tractor was a freebe when I bought the ranch. It sat outside for 12 years and I recall when I first fired it up, the bowl was completely full. I'm going to check into the aftermarket and thanks a bunch for that tip!

You know, that COULD be a possibility... the lever could be worn or bent and/or the cam could be worn, and the lever slips to the side and it quits operating the pump... should be leaving some wear marks if it's doing that, tho.

Does it then re-start, or only after the pump is taken off and then replaced again?

Also, there could be debris of some sort in the line, or a fitting, or at the tank outlet that stops up the gas flow, then floats out of the way after it quits and suction/flow ends.

Some years ago, my old GMC farm truck would quit from lack of gas at odd intervals.

After tearing the lines and fittings apart, I found a kernel of wild oats in a brass elbow at the pump that must have moved just right from time to time to stopper off the flow of gas. Never had and more trouble after that.

A customer had a 2010 diesel that would die from time to tome, and I suspected the IP.

It turned out to be a BIG horsefly lodged in the non-OEM fuel valve/fitting that had been installed at the tank outlet. The ports in the valve were rather large, and the insect was in a reducer fitting where the pipe size reduced down to fit the fuel line.

So you never know all the things that can happen!

Charlie Schmidt
Did you check for good fuel flow from tank and that the tank is venting?

Did your check valves fit snug in the body ?

The few of those type I worked on had worn pump body and the check valves would not seal up. Some JB weld solved that.

Yes when I loosen the bowl and lift the glass, the gas pours like niagra falls from the pump. I"m confident I don"t have a restriction. From a worn cam perspective does anyone know what the throw of the pump arm should be as it rides on and off the lobe? I"m guessing here but mine seems to be maybe a quarter of an inch at most. If I let the tractor sit long enough, there"s enough head pressue from the tank I think to fill the bowl far enough to start again. Here"s my next move because I do have about $45 into the kit... I"m going to remove and bench the pump with a 1/4 inch hose going into a jar of gas and another acting like the supply to the carb. To me, the gas should flow into the pump and not drain back out and it should flow to the "carb" and not drain back. Maybe if I"m feeling cleaver I"ll rig something up on my drill motor to replicate the cam...