DF254 injector pump oil level rising.

[cleat]

When tractor sits for a few days to weeks the level in the injection pump seems to rise on it's own.

This is the EPA pump with the little dipstick. When the dipstick is pulled to check oil level, a lot of oil/diesel spills out the dipstick tube.

Would this likely be the lift pump or the main pump ?

I have a suggestion from a DF dealer to separate the two and see where the leak is coming from. I will do that, I just have not had time yet.

If it is the lift pump, can it be repaired or must it be replaced ?

Thanks for any help, Cleat

 

[Bob Rooks]

It could be the lift pump or the barrel and plunger assemblies. Try shutting the fuel off at the tank when you're not using it and see if that makes a difference. The only thing serviceable in the lift pump is the O-ring on the cam follower shaft. But new lift pumps are only about $40. If it turns out to be the barrel and plunger assemblies, then you're looking at a new fuel injection pump because parts are not available. You could also fit an aftermarket fuel injection pump, like a Stanadyne, which are repairable, but you are still talking several hundred dollars.

 

[cleat]

That sounds easier than separating the two. I will give that a try before going any further.

I hope I can find a lift pump, seems DF parts are hard to find.

 

[Bob Rooks]

That sounds easier than separating the two. I will give that a try before going any further.

I hope I can find a lift pump, seems DF parts are hard to find.

Lift pumps are pretty universal. If your lift pump has three mounting holes in a triangle (two at the top, one at the bottom), and a large hex nut on the side, most any will work. There are two versions, one has the priming pump on the left, the other on the right. Affordable and Circle G stock them. A picture would be helpful tough, and a part number off the lift pump.
Curious what the dealer wanted you to separate?

 

[cleat]

I do not see any numbers on the lift pump. The injection pump has a paper tag attached but it is painted. Entire engine seems to be painted with thick black paint. I bought this tractor new and it came this way.

Engine plate says this (I think) Changchai 3LS25B which I also believe is a ZN390T.

These pics may help.

Thanks, Cleat

 

[Bob Rooks]

My bad - two on the bottom, one at the top. Just checked mine (I hate getting old). Yours has the priming pump on the left. The lift pumps aren't manufactured by the same company that makes the injector pumps. You'll want to remove the large hex nut before you remove it, there is a fairly stiff spring behind it. Install this last after the new pump is installed, makes it much easier. This, if you decide to replace it, or just replace the O-ring. Take care with the gasket too, you can re-use it with a thin film of RTV on both sides. Don't forget to drain the oil first. :thumbsup:

 

[cleat]

Where is this 'O' ring you talk about. Is it on the plunger shaft itself ?

 

[Bob Rooks]

Where is this 'O' ring you talk about. Is it on the plunger shaft itself ?

Yes, on the cam follower shaft. You have to disassemble the pump. Fairly easy, just make sure you don't get the little check valves mixed up.

 

[cleat]

Well, I drained the oil and put a clean pan under the pump. After 2 days only one drop in it so for now I just re installed the drain plug and added the 200ml of oil to bring the pump up to the full mark on the dipstick.

I will monitor the level and see. If the oil is coming from the high pressure side I guess I will just live with it until/if the pump fails then replace it.

Thanks, Cleat

 

[Bob Rooks]

Well, I drained the oil and put a clean pan under the pump. After 2 days only one drop in it so for now I just re installed the drain plug and added the 200ml of oil to bring the pump up to the full mark on the dipstick.

I will monitor the level and see. If the oil is coming from the high pressure side I guess I will just live with it until/if the pump fails then replace it.

Thanks, Cleat

Sounds like a good plan. If the leak is on the high pressure side it will have a negligible effect on performance, but because the fuel will dilute the lubricating oil, you will have to change oil more frequently.