Electric Lift Pump on Diesel Tractor

lenray · Feb 28, 2016

Have this John Deere 644 Loader tractor with the diesel engine. There is an electric lift pump to get the fuel from the fuel tank that sits down low in the tractor up to the injection pump.
The elecltric lift pump seems to kind of spit out the fuel compared to a smooth regular flow. Maybe take a minute or two to fill a gallon jug.
Does this seem about right or do they really flow the fuel?????????????????/

Jim Naden · Feb 28, 2016

(quoted from post at 12:48:23 02/28/16) Have this John Deere 644 Loader tractor with the diesel engine. There is an electric lift pump to get the fuel from the fuel tank that sits down low in the tractor up to the injection pump.
The elecltric lift pump seems to kind of spit out the fuel compared to a smooth regular flow. Maybe take a minute or two to fill a gallon jug.
Does this seem about right or do they really flow the fuel?????????????????/

Not at all familiar with that tractor but anything less than a strong, steady stream of fuel would seem inadequate in any situation.

Determined · Feb 28, 2016

(quoted from post at 14:48:23 02/28/16) Have this John Deere 644 Loader tractor with the diesel engine. There is an electric lift pump to get the fuel from the fuel tank that sits down low in the tractor up to the injection pump.
The elecltric lift pump seems to kind of spit out the fuel compared to a smooth regular flow. Maybe take a minute or two to fill a gallon jug.
Does this seem about right or do they really flow the fuel?????????????????/

I have a similar size Case wheel loader, same set up with the electric lift pump.
If yours is flowing a gallon in less than two minutes I would say yours is pumping more than mine.
Mine runs fine and has plenty of power the way it is.

Steve@Advance · Feb 28, 2016

I don't know what the flow rate should be, but spitting an intermittent stream does not sound right for an electric pump. Could be the pump is failing, or it's sucking air. Might try connecting a short piece of hose directly to the suction side of the pump into a container of fuel, see if it pumps better. If so, check for air leaks or a restriction. If it still pumps intermittently, likely a bad pump.

I have a Bobcat diesel. It was always hard to start, had to pump the primer bulb every time it was shut off for more than a few hours. Found out the mechanical lift pump was not working at all, but once it was running the injector pump would pull up enough to run. Replaced the pump and it now starts right up.

Billy Shafer · Feb 28, 2016

The pump should have a steady flow.Some do pulse and it may seem like they are spitting. But you should have a steady flow.

lenray · Feb 28, 2016

OK it takes 3 minutes to run 1 gallon of fuel thru the electric pump.................

Cliff Nelson · Feb 28, 2016

Also check the fuel supply to the electric pump. Restriction /plugged strainer in the tank could be starving the pump for fuel.

showcrop · Feb 28, 2016

A half gallon a minute would empty a thirty gallon tank in one hour. That would be a machine that would be hard to keep around.

vscummins · Feb 28, 2016

Hopefully somebody will have the spec for what it should be pumping but I would guess it should be closer to 2 or 3 gpm the excess fuel will be pumped back through the injection pump to the return on the fuel tank

tomNE · Feb 29, 2016

when I did mine; i went to napa and bought like a 1.5-2lb pump. It works nice. my tractor was designed not to need a pump but was never happy with how long it took to start. AC 7020 has the tanks down low. I couldn't be happier about the performance. Just something to provide fuel to the pump. these tractors have no bypass line like a semi does.

Tx Jim · Feb 29, 2016

I would think 1 gallon every 3 minutes would be sufficient fuel flow but the fuel spitting would concern me. No electric lift pump is listed in 644 parts catalog as only camshaft operated type is shown. I suggest to check for good fuel flow out of tank without the aid of a fuel pump. Have you checked to be sure tank is venting very well?

Electric Lift Pump on Diesel Tractor

lenray

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Jim Naden

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Determined

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Steve@Advance

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Billy Shafer

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lenray

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Cliff Nelson

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showcrop

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vscummins

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tomNE

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Tx Jim

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