Purging Injectors - Confused

ImaginaryTango

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Kubota BX25D
Jul 16, 2026
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Virginia, USA
I have a BX25D. I've cleaned the fuel tank, but there's still some fuel in the line. (I replaced the filters earlier, as part of the troubleshooting, so I think there's a good chance they're okay.)

I have seen a few sources, including Messick's, say that to purge air in the fuel line, there is no need to actually open up injectors so air can be forced out. On the other hand, I have friends saying, "Oh, no. That could really mess things up."

Which is true? Do I have to manually purge the injectors? I hear it's easy, but, I also need help with finding them. I know it's a 3 cylinder engine, so I assume there are 3 injectors. Are they sticking out from the cylinders or beside them? Where are they and is purging a matter of turning a valve and waiting until some fuel spills out instead of just air coming out? (That's how I've been told to purge them.)
 

John T

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2017 BX23S
May 5, 2017
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when I had the injectors tuned up on my New Holland skid steer....
I put them back in, and fired it up.
The way I understood it, the injector pump feeds the fuel and the return line brings any exess back to the tank .... air too, I would imagine.

Maybe I'm off base/not sure if the bota engine is the same....... but I had no issues.
 

North Idaho Wolfman

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I have a BX25D. I've cleaned the fuel tank, but there's still some fuel in the line. (I replaced the filters earlier, as part of the troubleshooting, so I think there's a good chance they're okay.)

I have seen a few sources, including Messick's, say that to purge air in the fuel line, there is no need to actually open up injectors so air can be forced out. On the other hand, I have friends saying, "Oh, no. That could really mess things up."

Which is true? Do I have to manually purge the injectors? I hear it's easy, but, I also need help with finding them. I know it's a 3 cylinder engine, so I assume there are 3 injectors. Are they sticking out from the cylinders or beside them? Where are they and is purging a matter of turning a valve and waiting until some fuel spills out instead of just air coming out? (That's how I've been told to purge them.)
You need to read the WSM! And learn the engine operations and components before you do something dangerous or damaging to the tractor or to yourself!

You should not have to deal with any of the high pressure side of the system in order to get it to run.
 

ImaginaryTango

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Kubota BX25D
Jul 16, 2026
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Virginia, USA
You need to read the WSM! And learn the engine operations and components before you do something dangerous or damaging to the tractor or to yourself!

You should not have to deal with any of the high pressure side of the system in order to get it to run.
So you're saying if I don't know what I"m doing, don't even try to purge the air from the injectors?
 

whitetiger

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So you're saying if I don't know what I"m doing, don't even try to purge the air from the injectors?
What North Idaho Wolfman is saying is don't just start fiddling with things you do not understand. There is no need to loosen any injection pipes.

With fuel in the tank, turn the key switch to the Run position to activate the electric fuel pump. Let the pump run for 30 seconds, turn the key switch to the Glow position for approx 5 seconds, and then start the tractor.

If it does not start within 10 seconds, stop cranking the engine, let the pump run for another 30 seconds, activate the glow plugs again for 5 seconds, and start the engine.
 
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ImaginaryTango

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Kubota BX25D
Jul 16, 2026
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Virginia, USA
We have a winner! šŸ˜‹

Follow the above information. ;)
Actually, the information in your first post was more useful than the attitude in this one and I am still not sure about just exactly what you are saying in that first one - that I don't need to bleed any air out at all?

I'm really trying to get clarity here, but I'm still not sure exactly what is being said.
 

North Idaho Wolfman

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Do not mess with the High pressure side of the fuel system.
This is everything from the injection pump and beyond.
So, DO NOT mess with any of that side of things, the air will bleed itself out on that system.
DO exactly as @whitetiger said in post number 5
 

EPIC

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Older diesels would occasionally require bleeding injectors when changing the fuel filters or other fuel components.

However, as I understand it newer diesel engines work at a much higher fuel pressure and are designed to self bleed.

I believe this is why you have seen conflicting information because both are true in some circumstances.

In any case don’t mess with injectors unless you know what you’re doing because it can be dangerous and expensive if you don’t do things correctly.
 
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