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Good day. Last year I bought a 790 with FEL and Backhoe with 147 hours on it. I tried to use the FEL and it jerked quite a bit. After research (thanks to this site) I changed all the fluids and cleaned the screen filter. It worked great for the last few hours I used it. I recently tried to use it and again, it's jerking like crazy. My reseach seems to indicate either a clogged fitting, bad oil, air in the system (rubber hose leak) or a dirty filter (screen). My question is, can I remove the screen filter without losing all the hydraulic oil? Anyone know what rubber hose may be the culprit? Thanks for all your help, much appreciated. :greentractorride:
 

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If it worked great after cleaning the screen - and now it isn't after a couple hours use - clean the screen again.

You aren't going to pull the screen without loosing most of your fluid. The best you could do is capture it in a very clean container, strain it twice, and reuse it. It's likely you will need to do this a couple times if the screen keeps getting clogged.

After 2-3 times of cleaning it you would hopefully be done - then you could add fresh fluid.

Curious to know - what all was clogging the screen? That could be a hint to what is going on.
 

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Stan gave spot-on advice. :good2:

Give us some more information on what happened and what was on the screen, we may be able to give better advice.
 

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Atlantahank,

I learned a trick a few years ago when I was trucking; I picked up a piece of tramp steel that cut the fuel return line on the truck's fuel tank, and had to replace the line and fitting on the bottom of the tank. And it had 100 gallons of fuel in it. I didn't believe that we would be able to replace the hose and fitting withoiut completely draining the tank. But we did in about 15 minutes. Slick as all get out.:yahoo:

If you have a wet/dry vac and someone to help you, using the cone suction tool, place it into the hydraulic oil fill with a rag around it to seal it. Also apply masking tape around the vent pipe to seal that. Once you start the vacuum and have a good pull, remove the plug that secures the filter and remove the filter and clean it. Keep a clean container under the drain, just in case. But you should be able to clean the filter and replace the filter and drain plug.

I used this method to install the transmission heater on my 955 without issue, which is very similar to removing the suction filter.

Dave
 

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What you likely have is yack growing in your hyd fluid due to water. Drain, remove clogged screen and filter. Try to wash out with diesel fuel or kero as best ya can with the screen and filter removed. Replace filter, reinstall screen. Fill with new fluid. May take more than once to get it all out. Now find out where the water is getting in. Most likely the rubber boot around the gear shift or a broken off vent line at rear if rockshaft area.
 

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Good suggestions

Good suggestions by others but I would ask if it's just the FEL that's jerking? If so, you may have a coupling problem and or an issue with the loader control. If it's just the loader, try removing and replacing the couplers going to the loader, cycling the loader in all directions, maybe even cracking the lines going to the cylinders and see if you have air bleeding out. If the backhoe is on the tractor, check the functions and remove and re-seat those couplers to make sure they aren't causing the issue even when using the FEL. Couplers are usually the weak point in hydraulics. O rings go bad, dirt and water can enter etc. so those are normally the first place I look for an issue with hydraulics. Fortunately they are also pretty inexpensive and easy to deal with.

If it's all hydraulic functions, then concentrate on more of a system issue like gunk/water in the fluid. Personally, I'd not worry about catching the fluid and recycling it. It's not cheap but lots less expensive than tearing into the tractor because water is trapped in the system and doesn't come out. You could also send a sample of the fluid out for analysis and that could tell you if there are excessive wear, water, contaminants in the fluid.

Treefarmer
 
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Discussion Starter #7
FEL Lerking

Good morning, I appreciate the feedback. The screen appeared to be clogged with thick oil, not significantly, but that strainer (filter screen) is pretty dense and it looks like it woudn't take much to clog it. I'll drain, clean, refill and let you know if it cures the issue. In addition, I'll recheck the backhoe to confirm whether or not it's affecting all the hydraulics. Thanks again.
 

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I agree with the above post, reseat all the hydraulic quick connects, they can look good but one can be just a little off and screw things up. It seems a little strange such a low hour machine would be plugging up the filter screen.
 

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Good morning, I appreciate the feedback. The screen appeared to be clogged with thick oil, not significantly, but that strainer (filter screen) is pretty dense and it looks like it woudn't take much to clog it. I'll drain, clean, refill and let you know if it cures the issue. In addition, I'll recheck the backhoe to confirm whether or not it's affecting all the hydraulics. Thanks again.
That “thick oil” or “yack” as xcopterdoc called it sounds like algae to me, I suspect it’s grown back.
 

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There are several threads about algae in hydraulic oil, but none that I read mentioned exactly what to use or how much.
They all seem to mention that the same algeacide thats used in diesel will work in hydraulic fluid, but Id pick one and call their tech support and ask.

One other possibility, if you have no water in the system, and no leaks from bad seals/boots.
I have had some old Hy-Gard, both regular and low viscosity, that separated or had quite a bit of dark "crud" in the bottom of the jugs. It was pretty old, but if it can happen sitting on a shelf, it can happen sitting in a tractor that doesnt see much use.
From the low hours, Id suspect it sat for very long periods.
If thats what happened, you may need another fluid change or two to get it all out.
Id suspect that even if its algae, and you use something to kill it, youd still need a change or two to get all the crud out...but xcopterdoc is the one that deals with that kind of thing a lot more regularly than most of us.
Id be interested to know if he has ever seen the fluid with that crud in it.

In my case, it was like the fluid itself was darker as well, but also had even darker stuff, resembled dirt, in the bottom of the jug.
 
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Discussion Starter #11
FEL Jerking * Update *

Good afternoon, this weekend I again drained the Hy-Gard J20D hydraulic oil, changed the transmission oil filter and the screen. The screen on the old filter was clogged big time. Not excactely sure what it is but once everything was changed and new oil added; it's woking fine again. Hopefully I got most of the gunk out. From the look of the filter I'm surprised the FEL worked at all. I now have a blistering 140 hours on this machine. Thanks for all your help. :thumbup1gif:
 

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Good afternoon, this weekend I again drained the Hy-Gard J20D hydraulic oil, changed the transmission oil filter and the screen. The screen on the old filter was clogged big time. Not excactely sure what it is but once everything was changed and new oil added; it's woking fine again. Hopefully I got most of the gunk out. From the look of the filter I'm surprised the FEL worked at all. I now have a blistering 140 hours on this machine. Thanks for all your help. :thumbup1gif:
Worst looking filter I've seen.
 

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That's pretty nasty stuff there. I use this algicide in my fuel: Biobor JF Diesel You might contact them and see if it's something that can be used in hydraulic fluid too.
 
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