To Bleed Or Not To Bleed?

[Industrial Toys]

Would someone kindly tell me what the difference is in one traditional Diesel engine that needs to be bled after running out of fuel and another doesn't. It sure is nice when you don't have to crack all those lines! Without a manual, how would one know?

 

[Leejohn]

I might be all wet on this but, the engines that you do not have to bleed have electric fuel pumps and they are pushing fuel thru the system all the way to the tank.

 

[Industrial Toys]

I was kind of thinking that too, but the lift pump only delivers fuel through the filter and to the injector pump. On models, I had to bleed, I had to go all the way to the injector itself.

 

[Tx Jim]

Too many variables to correctly answer. What tractor or engine. Was kill cable pulled(switch turned to off) as soon as engine sputtered????? Some engines are way easier to bleed the fuel than others. My Kubota M7040 is very easy to bleed and I owned a Ford 3000 that was worse than my ex-wife to get started when it was run out of fuel. Electric fuel pump won't remove the necessity to bleed injector pump as Leejohn stated if air has gotten in inj lines.

 

[Leejohn]

On my little 2 cyl kubota the shut off valve turns back open after a few sec, so when I turn the key on it is pumping fuel all the way to the injectors back to tank. My bx2660 has a fuel pump but I'm not sure about that one yet, the same with my L4240. The fuel shut off might not work the same as the 2 cyl does, but I know for sure on the 2 cyl I don't have to bleed other then let the fuel pump run for about 1 min. On my 7800 I have to bleed it by hand.

 

[Industrial Toys]

But why? What is the difference? Are some injector pumps different?

 

[Leejohn]

That I don't know.

 

[Coyote machine]

Not trying to be a wise guy, but the best way to avoid issues with having to prime or not is to pay close attention to the fuel level and add fuel BEFORE running dry. Another reason to do so is less chance of sucking up debris from the tank bottom.
If it can't be helped for some reason, then fill the filter, (after shutting off the petcock located before the filter housing), install the filled filter to it's bowl, put fuel in the tank an open the petcock and crank the engine for 15 seconds at a time, pausing in between times to not cook the starter or cook the battery. If after several attempts still no start then crack a line to allow air to escape and then crank again.

 

[Industrial Toys]

I rarely run out of fuel, except on my Mule. It starts again, although you have to crank it a lot. Just learned that there is a bleeder screw on the filter and a hand priming pump. Not sure if this will make it start faster. Next time I will try this.

I drained the Tank on my Kubota R510 yesterday, changed the fuel filter and it started up immediately, much to my relief.

Just got me to wondering why some and not others?

 

[Coyote machine]

I rarely run out of fuel, except on my Mule. It starts again, although you have to crank it a lot. Just learned that there is a bleeder screw on the filter and a hand priming pump. Not sure if this will make it start faster. Next time I will try this.

I drained the Tank on my Kubota R510 yesterday, changed the fuel filter and it started up immediately, much to my relief.

Just got me to wondering why some and not others?

The definitive answer: https://www.google.com/search?q=why...j7&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8

 

[Tx Jim]

On my little 2 cyl kubota the shut off valve turns back open after a few sec, so when I turn the key on it is pumping fuel all the way to the injectors back to tank. .

No electric fuel transfer(lift) pump will pump fuel into(through) injector lines therefore if inj lines have air in them they will need to be bleed manually. Granted the lift pump possibly could pump fuel through return line back to tank BUT that won't get air out of inj lines if it's present in inj lines. Granted some newer tractors are self bleeding but not ALL tractors are self bleeding when it comes to DIESEL

 

[crowbar032]

I have no idea. I accidentally ran my 953 Cat out of fuel and the manuel says to crack the fuel lines to bleed the air out as well. I'm lazy and didn't want to do that. So I removed the fuel filter (it was empty), filled it up with diesel and screwed it back on. About three cranks and it fired right up. This procedure was specifically singled out in the manuel as a "do not do this". I'm sure the manuel doesn't want it done this way as you run the risk of contamination in the filter and I spilled diesel on me/the loader/the ground.

Now that I think about it, almost every diesel manuel I've ever read says to bleed the lines when changing the fuel filter.

 

[Danny C]

I had a Cummins V6 diesel in an '83 Grimmer-Schmitt air compressor that did not need to be bled when run out of fuel. Just start it up and voilà! She cranked back up. the old 3 cylinder John Deere engines out of the old 310 backhoes were a bugger to bleed. I had two of them in air compressors (Sullair 175CFM & 185CFM) as well. #Nightmare

P.S. Pretty cool set up with the V6 Cummins diesel in the Grimmer-Schmitt too. She ws set up to run the engine on one cylinder bank while the other cylinder bank did the compressing of the air.