John Deere 4300 compact utility tractor hydraulic problem

[Prmc]

I have a 1999 model 4300 john Deere compact utility tractor with a 430 front end loader. It has 500+ hours on it. The hydraulic fluid and filter has been changed twice since new. There is a slow leak down on the front arms and bucket, even when the engine is operating. In addition the 3 point arms leak down, but raise again while the tractor is running. When the engine is off, both ends of the tractor leak down. This is not a new occurance, has been doing it for awhile, but is picking up the pace to the point of being a nuisance. Do I have a check valve leaking that's common to both hydraulic areas? I would appreciate some help on this from someone with far more experience than I. Sometime before I noticed this problem, I also bought a 485 backhoe for this unit and had the JD dealer install it. They put a skid plate on and "power Beyond" to have the flow the BH needed. Everything functioned well after that, but as I say, the problem is getting worse now. I am Thanking everyone in advance for your ideas and thoughts!

 

[DFB]

3pt and/or loader leak down when the tractor is off is a pretty normal occurrence so setting both ends to the ground when the tractor is shut down is just good operating practice

But more especially with some older 4000 series JD DSCV valves I seem to remember there had been long past forum discussions to how much loader valve leak down was acceptable (running or not)

I have some leak down numbers for my 4100 with a 410 loader but I cant remember where they came from

Now if the 3 point is cycling dropping and raising while running there could be other issues with the rockshaft cylinder or control valve but that's not what you're describing correct?.


The low vis oil recommend now for most hydrostatic use and especially when hot may exaggerate the leak down issue somewhat (just a guess on my part)

 

[J_J]

If your tractor is under warranty, the dealer has leak down rates that they will replace hyd components.

After warranty, it is up to you as how much leakage you can tolerate.

You could have multi problems such as valve leaking, cyl seals leaking both front and back.

 

[Prmc]

Thank you for your replies. The leak down occurs cyclically on the 3 point rock arms while the tractor is running. I will do a test today to see if I can be more sure of how often it occurs at idle and how much the arms move before it recharges and lifts again. The FEL will leak down whether running or not. I will also test the rate of leak down on it. I have gotten used to some leak down, but the condition has gotten more severe. I thank you for your input. When I finish using the tractor, I make sure both ends are solidly on the ground.

 

[Egon]

I've got a JD 4200 HST with 420 loader and #7 backhoe with 1200 hr. Both loader and hoe will leak down running or stopped. It's a nuisance at times but thinking of repair costs makes it very livable.