L2350 Getting air in fuel system

[ERICKUBOTAPA]

Hello, new member first post, i have a L2350 good running tractor, brought it in for service. Changed the fuel filter, tank has no shut off so i changed it quick and let the fuel fill the filter. I started tractor it ran for a minute and quit, i bled the filter, then bled the pump and then bled the lines at the injectors. Tractor will run for 20-30 seconds and quits, rebled everything and its got air again. Did this 3 times keeps getting air.
I ran i clear bypass line from tank to injection pump, to bypass filter to see if that was the issue, when i did this i notice right before the engine stalls out it dumps air and fuel out of the pump back toward the tank, this kills the engine.
Any ideas what would be cause air and fuel back pressuring from the pump to tank and getting air?

Tractor ran perfect before this, 1322 hours on it.

Thanks for any help.

 

[mikester]

Open the bleeder valve on the fuel line. RTM or find a manual online to help you locate the valve and proper bleeding procedure for your machine. This is the best way to get the air out of your lines.

The hard way is to keep starting and running your machine at full throttle to try and get the air out and prevent stalling the engine. Keep a charger handy if you choose this route, it will take you a while to purge the lines of air.

 

[pigdoc]

I have had to fiddle with fuel lines on my L2500 a couple of times in the last couple of years. When that fuel line gets old (we're in the realm of 30 years here!), it gets VERY brittle and prone to cracking. My L2500 has 1415 hours on it. The fuel line might be covered by a woven material against abrasion, so you may not see a crack. Top-of-list for me is to redo the fuel system with a better filter, a shutoff valve, and of course, new fuel lines. Someone else on this list probably has good knowledge of what kind of line to spec.

Also, does your tractor have a bleeder valve on the top of the injection pump like mine? Like this:

Very handy for draining the inevitable condensate out of the line. Just make sure it's closed up tight, or it could be letting air into the pump when the tractor is running.

-Paul

 

[ERICKUBOTAPA]

I have new fuel lines ordered for it.
The bleeder on the the pump is a little different, im going to start with the fuel lines and see where that goes.

Im wondering now if the pump gasket is leaking and letting air in.

 

[North Idaho Wolfman]

I have new fuel lines ordered for it.
The bleeder on the the pump is a little different, im going to start with the fuel lines and see where that goes.

Im wondering now if the pump gasket is leaking and letting air in.

If your talking the injection pump, NO not possible.
There is no gasket in that pump.
That pump should be under positive fuel pressure all the time.

It sounds like you either a blockage of fuel from tank or you have a vent in the cap that is causing it to build suction.