L4150DT Fuel Lines Bleeder issue

   / L4150DT Fuel Lines Bleeder issue #1  

nightowl490

Bronze Member
Joined
Mar 30, 2008
Messages
79
Location
Corrupt Illinois
Tractor
L4150DT
I shucked a fuel line to the injector pump which did kill the tractor. After getting to it decided to change out all lines from filter forward, changed fuel filter, selinoid, selinoid linkage. Also drained fuel out of tank and changed out petcock (had a small leak). My issue is this, I have repeated the bleeding process (via manual) repeatedly (12-15 times) and cannot get it to even puff/cough. I have bled before after refinishing fuel tank 2 years ago and don't recall this being so difficult. All lines are open, fuel in sediment "bulb", tank is full.

Any ideas?
By the way I also changed out a fuel line on top of motor between injectors that was cracking and looking frail.

Go Ronnie go at tractorsmart!
 
   / L4150DT Fuel Lines Bleeder issue
  • Thread Starter
#2  
Update, I started to pull lines starting with the bleeder to the top of motor= no fuel, filled tank to the gills and then fuel started flowing via motor. I saw there was 1/4 inch of fuel still in filter bulb. Fuel will not fill the filter totally...? I have fuel bleeding from the motor to the filter bulb but not into the bulb? Went from the other direction and new petcock is flowing great...spillllllage. Had to stop for domestic purposes. Has to be a fuel pickup problem. I cannot get to it again until next week. Can you damage a pump when running it dry for only a few seconds? I think I'm on the right track but getting a little bit nervous.
 
   / L4150DT Fuel Lines Bleeder issue #3  
With all the dis-assembly you may just have some air in the system. Loosen the injector pipe nuts 1/4 turn and run the starter until they get wet. Then it should cough to life.

The injection pump wouldn't be hurt by running out of fuel. The transfer pump shouldn't care either, but it may have picked now to die. It's a regular diaphragm pump so a leak can stop it pumping. It can be checked by unbolting it and operating the lever by hand and feeling the ports for suction and pressure. (make sure transfer pump pipes aren't swapped)
 
Last edited:
   / L4150DT Fuel Lines Bleeder issue
  • Thread Starter
#4  
With all the dis-assembly you may just have some air in the system. Loosen the injector pipe nuts 1/4 turn and run the starter until they get wet. Then it should cough to life.

The injection pump wouldn't be hurt by running out of fuel. The transfer pump shouldn't care either, but it may have picked now to die. It's a regular diaphragm pump so a leak can stop it pumping. It can be checked by unbolting it and operating the lever by hand and feeling the ports for suction and pressure. (make sure transfer pump pipes aren't swapped)

Mr. Bargeron, You were right on with all the air out of system. I kept at it with loosening lines to and from the fuel filter, fuel everywhere, except in the bowl?. I still had quarter inch of air in the filter bowl and could not figure it out. I finally loosened filter bowl and fuel started to fill the remaing sediment bulb. The sediment bulb was too tight...... as soon as I relieved pressure fuel flowed into bulb....down my arms....etc.. I must have had it way too tight and the O-rings were not seating? Anyhow, one bleeding phase and it coughed to life and ran great......

There is now and handwritten note in my workshop manual to HAND TIGHTEN SNUG fuel bulb.

It's funny how I was looking at the package advertisements for the L48's, box blade, shredder, cash price this and that. There is something to be said for an old tractor that WANTS to run....

Thank you for being here and I respect your posts.


Regards,

Mark
 
   / L4150DT Fuel Lines Bleeder issue #5  
I had a very difficult time bleeding the air if my L4150 ran dry. or when changing the filter. I finally found that the venting hose from the fuel bowl that loops up above the bowl under the hood was too long which made the hose kink. So when you tried to get fuel to flow to the bowl it would not. I replaced the tubing and made it shorter. It now works as designed. The kink prevented the fuel from being bled through the filter bowl and out the tube into a container hopefully.
 
 
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