JD 440 gas hydraulic troubles- oil going into engine.

[dondeere]

I just bought a 59 JD 440 from a fellow and he said the hydraulic oil was low that is why the blade was slow. I took it home and filled up the hydraulic tank. Right after that it started to miss and burn oil. I checked everything and it still missed and the rear plug was fouled. It sat in my yard a few weeks and then noticed the hydraulic tank was low again, it was filled again and then I used the machine and noticed more and more blue smoke. I checked the engine oil dipstick and now see that the hydraulic oil is leaking into the engine, that is why the engine is burning oil as it is way overfull. I assume the pump is the culprit, how hard it it to fix this problem? Has anyone ever had this problem before?, I am obviously not amused at the guy that sold it to me. I do not have a manual so I don't know how much work this would be to fix it.

It is a 440 crawler with a 420 engine put in it.

[Lavoy]

You will have to rebuild the pump. Not a lot of work, but some, I keep most or all of the parts on hand. Get a factory service manual prior to tackling.
Lavoy

[dondeere]

where do I find a pump?, what are the steps to getting the pump off the engine?

its a 420 engine in a 440 chassis.

[Lavoy]

No need to buy a pump, fix the one you have.
Pump is on the front of the engine, end of the camshaft. Service manual will have disassembly and repair directions.
Lavoy

[dondeere]

can you advise where I can buy a manual?

[DukeofDeere]

Best manual is straight from Deere.
Better than an IT manual.

Duke

[Lavoy]

Deere sells paper, CD, and downloadable versions, you can also check on Ebay.
Two of my suppliers just started carrying manuals, so I can get them for you now as well, but I think the price on the 440 manual is too expensive, ($85), but it is 334 pages long, so maybe not.
Lavoy

[Paul Buhler]

Try here for a free parts manual from John Deere. Type in "420" for your model number to view and download the needed .pdf This will give you an idea of what the pump has for parts. You can do this for other models as well. Paul

http://jdpc.deere.com/jdpc/servlet/com. ... ervlet_Alt

[dondeere]

Ok, got the pump off today, not too much trouble, pump actually looks pretty clean and may have been rebuilt at one time, from the looks of the parts book it shows only an O ring and some gaskets, I am not sure how the oil could have got through and then in the engine.
Does anyone know if there is supposed to be a seal on the engine side, to keep the engine oil in and the hydraulic oil in?
The parts book does not show one.
Where do I find a rebuilt kit for the hydraulic pump or can I just use generic O rings?

[Lavoy]

Should be an o-ring and a backup on the shaft. Another thing to check is the bypass pressure, if it is set too high, that might contribute as well.
Lavoy

[dondeere]

how do I check the bypass pressure?, is there not a relief valve?, would it be in the pump or the control valve.

[dondeere]

also while removing the radiator, I noticed oil in the antifreeze and the hydraulic oil is milky, not sure what is going on.
any ideas?

[Lavoy]

Oil in the antifreeze is a head gasket leak, maybe cracked head.
Water in the hyd oil is a moisture problem, or possibly rain water getting in the tank somehow if the crawler sits outside.
Relief is in the valve, you will need a hyd pressure gauge to check.
Lavoy

[dondeere]

it keeps getting worse, I went from buying a "excellent" running crawler with no issues that "he" knows of to a giant paper weight with issue after issue, got to love guys who tell you "its good".

[Lavoy]

I hate to say it, but this seems to be the way most of them are advertised. I have talked to so many customers over the years that have been lied to by the seller, that it is not even funny.
It could also be the truth. I sold my fully restored 420 many years ago to a guy, and he no sooner got it home and started using it, and it develeloped a head gasket leak, or had been leaking, and I missed it, so it is possible.
Lavoy