6341 fuel system leaks down and have to bleed if it sits overnight

[jbjbeene]

I replaced the manual pump with an electric fuel pump after could not get tractor to start. Installed and bled system and it starts but it will bleed down over night and have to bleed air again to start. I assume it has to get air between tank and fuel pump. any suggestions

 

[ixer0]

Hi,

Clamp the return line and pressurize the system with the hand primer. It should show up a fuel leak which will let air in overnight.

Mike

 

[colinoleary]

MINE DOES SOMETHING SIMILAR
it just swings a lot in morning if i dont pump the manual primer and she starts first pic then
where do u think this diesel i leaking back?

 

[hala]

Classical problem! Change all hoses to new ones and make sure to get it tight. A week point is the glassbowel that can let air in even if you don't see fuel leaking out. Most important do not forget the hoses from the injectors back to the injectionpump. Some dealers put a small tank between the return hoses and the tank on a high level so fuel can be fed back. I admit this is not a perfect solution but it helps. A check valve close to the tank helps. A very tricky problem. Look for similar problems in the forum.
Hazze

 

[slowalker]

I had a similar problem and it turnrd out it was the copper washer that connects the fuel supply to the glass bowl ,I found the leak by pumping the hand pump till it got hard and then pumped some more and saw little bubbles coming from the washer, I tryed to tighten it but it was tight so I really tightened it .It didn't feel like it really moved but it must have because the bubbles stopped and she has worked perfect ever since.

 

[big_orn]

I know this is an old thread, but we never heard back on this.
The fuel is pulled from the tank to the pump, first via the the bowl. The connection on the banjo fitting (on top of the bowl) can suck air and you won't know it. Those washers that seal the banjo (and all banjos on the fuel system) have a rubber seal made into them. If that seal is crushed enough, it will not seal and allow air into the system.
Also, start at the most simplest parts first. Sometimes a new fuel filter will fail. They get clogged with fungus and blocks flow. Not very common, but common enough. Use and anti-fungal additive if you live in those areas where those conditions are prevalent.
(1) Pump fuel system by hand until pressure is built up.
(2) Loosen connection on injection pump and see if flow is good. If not follow that line backwards until you find the culprit.
(3) If you have good flow to the injection pump, then it could be the pump or the lines obstructed or the injectors are clogged/damaged.