JD 4300 hydraulic screen clogged over and over

[Egon]

Use a cheaper brand for flushing and then go to the one you want.

Does the grayish sludge settle out when the oil sits? If so you could use the clean portion for flushing.

Any hydraulic attachments that could have had contaminated oil in them?

Show a sample to your dealer if you don't get it tested.

 

[dfkrug]

I will check for the breather tube.

I believe the only vent in the sump is the fluid fill cap. The hole is tiny and
it can be compromised by dirt. JD has since gone to a tall black vented refill
cap to replace the yellow original one.

As for hyd fluid, your owner's manual says replace every 400 hrs, which
applies to most tractors, and you generally don't need low viscosity (J20D)
unless you operate below 0F. You can buy regular J20C-equivalent oil for less
than $10/gal if you look for it. Make sure the label says it is equivalent
to J20C/UDT/etc. I have used lots of Chevron 1000THF and Conoco76
THF.

 

[arrabil]

JD has since gone to a tall black vented refill cap to replace the yellow original one.

dfkrug, can that be retrofitted to the 42/43/4400?

I think I'm going to buy the service manual hopefully its well written and reasonable.

The service manual is well written indeed. And its extra reasonable if you get it off eBay.

So how many times have you changed the oil and checked the filter in the 8yrs/250hrs? I leave mine outside all the time including in the winter and the oil is clear. I think I would drain all the oil, leave the screen filter out and open, and gently soak areas of the tractor with a hose until I found where the water comes in at (you'll know when water is coming out the filter opening).

You also said the tractor has been unreliable.... what else is wrong with it?

 

[beenthere]

...................
You also said the tractor has been unreliable.... what else is wrong with it?

I think someone is trying to convince Dad into buying a Kubota.

 

[dfkrug]

dfkrug, can that be retrofitted to the 42/43/4400?

Yes, if you order a replacement cap, they send you the new one.

You can see it in one of my 4300 thread pix here.

 

[arrabil]

Would you actually the spend the few bucks to replace it?

 

[RoyJackson]

john_5657 really needs to find out what that sludge is. I'd strongly suggest he have a sample analyzed.
My guess...only a guess...is it's an algae or bacteria of some sort. There are anti-bacteriological additives.

 

[jpinca]

[copied over from duplicate thread]

Assuming you are using the correct fluid, the only thing I can think of is that would be inside the system and is gray and non-magnetic would be Al particles. I haven't seen water in tractor fluid, but I thought water and oil normally creates a white, frothy concoction. (this would make for a quick experiment).

How thoroughly did you flush the case after the previous clogs? I ask because this may have been a one time event with insufficient cleaning or an ongoing problem.

Not sure if this would be helpful, but you may be able to identify to contaminant by putting some of the sludge through coffee filters with help from a solvent (acetone or lacquer thinner, etc). Eventually the solids (assuming there are) will separate from the oil. Silver/grey dust would be Al. I've never tried this- mostly I'm thinking out loud.

 

[arrabil]

is it's an algae or bacteria of some sort

Wow, what a yummy thought Roy!

 

[RoyJackson]

Wow, what a yummy thought Roy!

Makes a great soup, once you strain out the hydraulic fluid!!

I was serious though. Hydrocarbons can be susceptable to bacteria attack. I can't think of too much else that would cause a sludge build up, other then the hydraulic fluid being contaminated by something like a rubber or plastic compound that was breaking down. As any rubber or plastic used in a hydraulic system should be of a compound that is resistant to hydraulic fluid deterioration (unless something was dropped in the tank or a hose was replaced with one not made from resistant materials), there's not much else.

At this point, I'd flush the system thoroughly, replace the fluid/filters (using Deere hydraulic fluid and filters) and see what happens.