How to change fuel filter on NH 3930

[AlbertC]

I am past due on changing the fuel filter on my NH 3930. I have never changed it because I don’t really know how and am concerned that I might screw it up and not be able to start the tractor. I am aware that if you let t diesel run out of fuel or get air in the lines it can be hard to fix.

I have attached pics of the current filter set up and a pic of the inline valve that I would assume you have to turn off before you remove the existing filter. I think this current filter set up is a modification from when the tractor was new. Can anyone walk me thru how to change this filter so that I don’t encounter any problems with it?

Thanks

 

[TractorTech]

That is original on the emissionized engine.
Before you start, make sure you have at least a half tank of fuel. Turn the fuel off. Unscrew the black ring at the top of the filter and pull the filter down. Look to make sure there are not any seals stuck in the filter head. Push the new filter into the filter head tighten the lock ring. Turn the fuel on. Now loosen the large cap at the top of the filter head and let fuel run out until few bubbles are noted. Tighten the cap back. Set your throttle to about half speed and start the tractor.

 

[Lineman North Florida]

Good info above, the only thing I would do different is fill the new filter full of diesel fuel before installing it.

 

[Harry in Ky]

I don't worry about filling the filter, that's what bleeding is for. More importantly, with that style system you have no bleeder on the pump. For a novice who doesn't want to get caught with an air bubble, I would suggest you reach in and pull the wire off the shut off solenoid. After bleeding the filter I would crank the engine over at least five or six revolutions before putting the wire back on. Maybe even a little more. You stand a better chance of eliminating any air between the filter and the pump that way and minimize the possibility it will start then die two seconds later requiring bleeding the injector lines as well.

 

[Lineman North Florida]

Different strokes for different folks, either way the new filter has to be filled with fuel, I like to see it full .

 

[AlbertC]

That is original on the emissionized engine.
Before you start, make sure you have at least a half tank of fuel. Turn the fuel off. Unscrew the black ring at the top of the filter and pull the filter down. Look to make sure there are not any seals stuck in the filter head. Push the new filter into the filter head tighten the lock ring. Turn the fuel on. Now loosen the large cap at the top of the filter head and let fuel run out until few bubbles are noted. Tighten the cap back. Set your throttle to about half speed and start the tractor.

? Nowloosen the large cap at the top of the filter head and let fuel run out until a few bubbles are noted?

Where does the fuel run out at? The cap looks like it has holes in the top of it. Is this where the fuel will run out? And do I initially want to see solid fuel run out of these holes and then subsequently see bubbles? When I see bubbles, I’m good?

Thanks

 

[AlbertC]

I don't worry about filling the filter, that's what bleeding is for. More importantly, with that style system you have no bleeder on the pump. For a novice who doesn't want to get caught with an air bubble, I would suggest you reach in and pull the wire off the shut off solenoid. After bleeding the filter I would crank the engine over at least five or six revolutions before putting the wire back on. Maybe even a little more. You stand a better chance of eliminating any air between the filter and the pump that way and minimize the possibility it will start then die two seconds later requiring bleeding the injector lines as well.

? I would suggest you reach in and pull the wire off the **** off solenoid? Where is this at? Do t really know what the shut off solenoid is or what it looks like.

Thanks

 

[TractorTech]

? Nowloosen the large cap at the top of the filter head and let fuel run out until a few bubbles are noted?

Where does the fuel run out at? The cap looks like it has holes in the top of it. Is this where the fuel will run out? And do I initially want to see solid fuel run out of these holes and then subsequently see bubbles? When I see bubbles, I’m good?

Thanks

The fuel runs out under the cap. I should say, you are bleeding the air out of the filter, so run the fuel out from under the cap until you see few or no bubbles. Filling the filter with fuel first will keep from having to bleed so much out to get rid of the air.

The solenoid is located on the back of the injection pump and is usually attached with a screw on this model, so not easy to remove. If you bleed the filter as instructed and have the throttle at half or above half, it may falter when starting, but recover until all the air is out.

 

[AlbertC]

The fuel runs out under the cap. I should say, you are bleeding the air out of the filter, so run the fuel out from under the cap until you see few or no bubbles. Filling the filter with fuel first will keep from having to bleed so much out to get rid of the air.

The solenoid is located on the back of the injection pump and is usually attached with a screw on this model, so not easy to remove. If you bleed the filter as instructed and have the throttle at half or above half, it may falter when starting, but recover until all the air is out.

Thank you and the others for the advice in trying to help me with this issue. But I still don’t feel confident that I can do this without screwing it up. I’m not really mechanically inclined. I guess I need to try to find someone who can show me how to do it.

But, once again, thank you for trying.

 

[Lineman North Florida]

Thank you and the others for the advice in trying to help me with this issue. But I still don’t feel confident that I can do this without screwing it up. I’m not really mechanically inclined. I guess I need to try to find someone who can show me how to do it.

But, once again, thank you for trying.

If there are any farmers around you, you can bet that they know how to do it and can show you so you can do it in the future, as it really is a simple procedure once you see it.