Irratic Hydraulics

[RLStroope]

Need some advice. I have a 2000 JD 4600 4wd with power reverser with 268 hours. Last month I lost all hydraulics. I learned that even though the hours were low the transmission/hydraulic the oil can get contaminated with fungus. Sure enough when I drained the oil, changed the filter and cleaned the screen and filled with new oil all was good. Now a month later the hydraulics are acting up again. Fired it up this morning and noticed that when it is in gear what I think is the pump is making a straining sound. Gets louder when the steering wheel is turned. The operation of the loader seems to be erratic and not fully there. Is there something I missed? The local JD service center told me to add diesel fuel stabilizer when I change oil which I have not done yet, but I think it would be too soon for gunk to build up again. Thanks in advance for any suggestions.

 

[Soundguy]

Some JD's have a suction strainer and a filter.. the suction strainer is usually washable...

does your's have this.. and did you service it?

soundguy

 

[kennyd]

Welcome to TBN

The "fungus" thing is sure a new one on me...I'd be willing to bet you have a leak on the SUCTION side of the pump somewhere causing the fluid to get foamy, then the pump cavitates. Check the large steel line under the trctor, and follow it towards the front-there is a rubber hose on it where it connects to the pump that can split.

 

[RLStroope]

Aparently the fungus is a result of condensation building up in the gear case and fluid lines when a tractor is not run frequently. The fungus then clogs the suction screen and filter. I spoke with the JD service folks today and they told me that they have in the past had to fill the gear box with diesel fuel and let it sit a couple of days to kill the fungus. I checked all the lines and everything is solid, so that means that even though I changed the filter and oil and cleaned the suction screen, there was a residue of fungus remaining on the walls of the gear box and fluid lines that is starting to clog the screen and filter once again. I normally keep my tractor inside but this summer had to leave it outside under a tarp. The hot ambient air here in Central TX. must have caused condensation to form. I am going to add some diesel fuel stabilizer today and run the tractor to circulate the transmission fluid to see if that helps any. If not, I am going to have to drain the transmission again, clean the screen, fill with diesel, let that sit for a day or two, then drain that and put in new oil and filter. Must be a better way.

 

[RLStroope]

Let me clarify, the hydraulic lines are solid, i.e. not leaking so I do not think there is air in the lines problem.

 

[john_bud]

Let me clarify, the hydraulic lines are solid, i.e. not leaking so I do not think there is air in the lines problem.

If the screen clogs up, the pump starves and pulls so hard it draws vacuum and makes bubbles. That's cavitation. Those bubbles are like sandblasting the pump.

If you have some creeping crud inside the tractor, you need to get it out or you will be weeping over the damage to your wallet. I would change the fluid, clean the strainer and put on new filters and right away add a diesel fuel BIOCIDE. Heck, I would add double strength BEFORE changing the fluid to try and kill as much as possible. Then add double strenght to the new fluid


jb

 

[RLStroope]

Since changing the filter, cleaning the screen and adding new oil the hydraulics have bogged down again. I just drained the oil and the screen is clogged again. JD service told me to fill the transmission with diesel fuel and let set for a few days. May have to run the tractor a little to ensure gets through the system. They say drain diesel and add new fluid, filter and a little biocide. My question is, has anyone run diesel through their hydraulic system and if so how did you get all of it out? I would think you would have to flush the system with clean oil several times to ensure all the diesel was out.

 

[Soundguy]

The diesel will mix with the new oil you put in the first time, thinning it...

I wouldn't run it to lond with diesel in it.. it will likely cavitate badly under load.. etc..

soundguy

 

[Nasty135]

Just caught this post and have noticed your trouble and possible remedy...

I was surfing and caught http://www.kennedydiesel.com/ with a product called "killem" in the fuel treatment section that is supposed to wipe-out fuel/oil related fungi.... maybe worth a try hydraulic oil changes ain't cheap... and you might be able to just leave it in with out noticiable side effects "maybe, hopefully" since it is only 16oz.

Good Luck...