John Deere 950 Diesel Fuel System Issues

[Bladerunner6]

I am having problems with my John Deere 950 tractor.

I was having problems with the tractor losing power and thought it may be the fuel filter. I changed the filter and bled the lines precisely in accordance with the operators manual.

The tractor will start and idle, but when operated it will lose power and the engine stops.

What I have done so far is:
1. Change the fuel filter.
2. With fuel turned on, I loosened both bleed screws above the fuel filter.
3. Loosened the bleed screw on the injector pump.

After the above, it would crank, but when operated would lose power and die.

So then I bled the injection lines.

1.Loosened all 3 lines at fuel injectors.
2. Loosened Number 1 and Number 3 delivery valve holders 1/4 turn.
3. Fuel was supposed to appear at Number 1 and 3 fuel injectors. This never happened unless I tried to crank it, then fuel would appear.
4. I tightened everything back up and tried to crank it.
5. The tractor runs but there is a steady stream of air bubbles visible in the fuel sediment bowl. It will idle, but will die when operated for a couple of minutes.

I thought it might be a bad seal with the rubber "O" ring around the fuel sediment bowl, so I ordered a new one. It hasn't arrived yet.

Does anyone have any ideas on what I am doing wrong. I hate to take this to a JD dealer, it will cost me a small fortune.

 

[Bladerunner6]

Moving this over to general John Deere forum

 

[Tx Jim]

The air bubbles in sediment indicate that the fuel system is sucking air somewhere. I will guess that the fuel filter isn't sealed properly but it could also be a hole inthe fuel line.. Have you checked to be sure that you have good fuel flow out of fuel tank?? Is fuel tank vent not plugged. FYI fuel should only come out of injector lines while engine is turning over hence he name fuel injector "pump".

 

[bmaverick]

We replaced the fuel hose line from the fuel tank to the fuel filter, then from the filter to the fuel pump. The problem then went away. Also, we didn't use worm screw clamps, only constant spring clamps. The fuel hose is the Goodyear Gator high pressure type. It will last years in the outdoor environment.