JD 4200 Hydraulic Issues

baberes · Dec 11, 2008

I have an 2001 model 4200 with fewer than 250 hours. I'm starting to have a repeated problem with the hydraulic system getting gunked up. I've changed the fluid and filters twice, and cleaned the screen at least 4 times in the last 18 months. But the screen continues to get clogged. I asked my JD dealer what could be the problem (i.e., what in the heck am I doing wrong). He said it's a known issue for the hydraulics to "gunk up". The suggestion he gave me is a bit odd - drain the fluid, fill with diesel, rock the tractor to swish it around, drain the diesel, REPEAT. Then pull off the PTO plate, get all the gunk out, replace filters, refill with oil.

Before I undertake such a mess, does anyone else have this problem? Does this "fix" seem extreme to you?

Thanks!

dirtworksequip · Dec 11, 2008

I have heard of using diesel to clean a hyd. system. You say it is getting "gunked up". What does it look like? We need more info.

Sincerely, Dirt

kennyd · Dec 11, 2008

More info needed, could be a fungus growing in you hydraulic fluid? Might need a biocide (like used in diesel fuel) to kill it...

RogerH · Dec 11, 2008

I agree with kennyd that you might be dealing with a fungus or algae growth issue. This can happen in petroleum products, especially if a small amount of water is present.

It appears that this tractor averages ~30-40 hrs per year of use. This means it is spending most of its life sitting, giving time for bio-things to grow. I would first look for potential ways for water to get inside. The hydraulic oil fill cap from this date was not particularly good at excluding water. If it is of the type with the small little plastic ball in the center, consider replacing it with the newer design.

I would also suggest running it more often, just to get the oil hot. That will help evaporate water and kill off mold/algae/fungus.

The diesel fuel flush your dealer mentioned is a real procedure. I have never done it, but have seen the service bulletin that describes it.

Mighty Dodge · Dec 11, 2008

I agree with the others. Sounds like you've got moisture in the system which could also cause algae growth. Is the gunk in the screen foamy or discolored?
That's mighty low hours on a 7 year old tractor. I remember reading somewhere that one of the leading causes of hst problems was not running enough hours to evaporate off any condensation that forms in the transmission. Mine gets around 100 hours a year now. When I bought it two years ago had 370 hours. The dealer was supposed to have changed the transmission fluid before delivery. I plan on changing it again in the next week or so.

M.D.

mjncad · Dec 12, 2008

Baberes, I have a 2001 4200 with about 475 hours on it and I don't have the problems you describe.

I live in Colorado and our dry climate tends to eliminate the hassles of condensation related problems that others deal with. Where are you located?

I've attached three pages from the shop manual for yanking off the rear PTO plate to help you decide whether you want to tackle this yourself.

baberes · Dec 12, 2008

You're right, it does sit idle A LOT. I'm in North Texas and our temps can be extreme and I was thinking I had a moisture problem as well. Since I didn't observe any leaks, I figured condensation was the culprit, but it sure is a lot of moisture in the system b/c it brings the tractor to a grinding halt.

The gunk, if you'll pardon my analogy, is like mucus - turns white-ish and gets lumpy. I'm able to clean the screen just fine, no damage to it.

If the fix is running more hours, then I think it's time to sell. I like having it around for the big jobs, but don't need the aggravation. Hopefully I can find someone who needs it more than I do.

baberes · Dec 12, 2008

mjncad - Thanks for the file. It's just as "involved" as I thought it would be and you confirmed it!

mfreund · Dec 12, 2008

An idea, Run an ad in the local paper looking for a partner for ownership. If you could find someone close that also needs a part-time tractor it could work. But then it might be more headache than selling and renting when needed