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Loader piston question

3K views 7 replies 4 participants last post by  makoguy 
#1 ·
I've got a 2001 Bx2200 with what I've come to think is a malfunctioning center piston on the FEL. I've noticed a marked decline in the lifting and digging abilities of both my back hoe and front end loader. Now after checking pretty much every fitting for leaks/tightness, having a dealer do a full fluid change and check-up, and finding nothing to make me think a filter is clogged or that there was a hose or fitting sucking air into the system I came across a problem on the bucket. It seems that my ramming the tractor into trees, stumps, or otherwise fairly immovable objects has worn down the steel tabs that stop the bucket from coming back to far. They are worn so badly that they only touch if I were to push the bucket against something with the bucket rolled back all the way. Quit a bit of play in it also. After noticing this I have found that the pressure relief valve doesn't make nearly the same high pitched sound when I hold the bucket in the roll back position as say when I hold the 3pt in the up position continuously. I'm sure the arm on the piston has been forced back further than was intended and am wondering if this could be what has led to the loss of power. I'm thinking there may be some blow by going on, but the cylinder doesn't seem to be getting to hot in any particular spot other than around where the hoses connect to it. Anyone ran across something like this? Everything is still working fine, but just not quite as good as it used too. The arm is still straight and no leaks. I'm thinking of just taking it off and having it rebuilt. My usual dealer is back logged is why I'm even messing with this instead of just dropping the tractor off and having someone who knows more about it just fix it. To many projects going on and need my tractor for them, even if the FEL is for counter weight only for awhile. Thanks for any and all feedback!
 
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#2 ·
Being as you've seen a decline in performance at BOTH ends of your tractor, I think you need to check the system pressure in your hydraulic circuit. It may be that a relief valve is stuck open and lowering your overall pressure, or that your pump is failing/wearing out.
 
#3 · (Edited)
The dealer said they checked the pressure and it was within range at that time, but I've used it quit a bit since then so it probably needs to be checked again. I do not have gauges yet, myself. I also found some info on how to check the cylinder itself and plan on trying that this afternoon. This should at least tell me if it is what I think it is. The problem is at both ends, but it seems at least to me to be more in the bucket end of it. Used to I could fill the bucket up with dirt and it would roll it back no problem. I could lay the bucket flat on the ground and tilt it over and up came the tractor. Now it struggles with the dirt and won't lift it with the bucket. The back hoe still will pick up the rear end and move it around, but the bucket seems to be getting stuck easier. I've really abused this poor little machine and to Kubota's credit, it has held up far better than I would have ever expected.

Thanks for the help....Stephen
 
#4 ·
Well, with the new info that only the bucket and loader cylinders have issues, I'd say it sounds like you've been asking a lot of your machine. Now it's returning the favor and asking for a bit of maintenance to the cylinder seals! I would try testing the seals one way by putting the bucket at an angle to the ground (45 or so) and use the boom or dipperstick to lift one end of the tractor a bit. Watch the bucket and see if it drifts to relieve the pressure. If it does you're likely either looking at cylinder or valve seals going bad.

Using the tractor to pull/push or pry with the bucket with the valves centered WILL overload the PSI rating of the cylinders/valves, causing seal failures. The pressure reliefs in most systems are on the 'P'ressure side of the valve assembly, and as such cannot relieve pressures within the cylinder caused by suddenly loading the bucket with the valve centered. Yes, I also use the bucket in combination with the tractors power to push over trees or move things, but always be mindful of the pressures you may be creating within the cylinders. Overloading the cylinders can also cause sudden (and possibly catastrophic/fatal) bursting of the hydraulic hoses on your equipment!!
 
#5 ·
Yes, it really deserves some serious maintenance. I would say at best I've used it to say push or pull trees with the bucket, but in reality I have used it more as a battering-ram when push came to shove. That's why I'm leaning towards the center piston up front. Hoping that's all it is and not like several things. On my last stump removal project I managed to shear off a bolt on the frame mount for the FEL and also sheared one of the roll pins for one of the universal joints for the drive shaft going to the front wheels. Then sheared a grade 8 bolt I put back in instead of the roll pin. Need I say my bucket sits a little bit crooked because the arms are a little bit warped? Even rental equipment leads a decent life compaired to my little orange buddy, but I sure do love it even if I don't show it some!
 
#6 ·
USE CARE with this test.

-Disconnect the rod end of the suspect cylinder.
-Use tractor hydraulics to extend it fully.
-Disconnect hydraulic hose for the rod end of the cylinder, at the loader end.
-Put the end of that hose in a clean bucket, and secure it.
-Start the tractor and extend that cylinder again. DO NOT RETRACT!!!!!

-If a stream of fluid comes out of the hose, the piston needs to be re-packed.
-If it only drips, your problem is elsewhere.

-Shut off the tractor and reconnect the hose and cylinder if okay, or finish removing the cylinder for repair if required.

-Once removed, place the cylinder end in the oil bucket and push down on the rod end to collapse it and purge the oil from the cylinder. Now there is a minimum of oil to contend with when the cylinder is disassembled, either by you or the repair shop.

A glycerine filled 5,000 psi pressure guage costs about $20. That plus the appropriate 'T' fitting will eliminate doing this kind of test and can be used anywhere on the system to locate specific problems.

Bob :rauch10:
 
#7 ·
Welcome aboard makoguy. JRC0528 & TUDOR are spot on w/their troubleshooting.

In rereading your posts, I can't see where the stops on the FEL being worn would effect the hydraulic performance of the BH so I tend to think the pressure is off also.
There are several kits available to both test and adjust a BX's hydraulic system pressure. One such is made by www.bxpanded.com
Basically you can add additional shims to the main relief valve which is how you adjust system wide operating pressure. Instructions are included.
Those BX2200's are getting some serious hrs on them and yet they're still very stout. Everything wears over time. Alittle maintenance will extend their lifespan out even more.
Let us know
Dave
 
#8 ·
Bob, I missed your post yesterday before I got started doing some checking, but I found what I think is the culprit anyway. As Dave stated, it was not the stops being worn. I blocked off the bucket arms and did some hose play to see if the bucket would drop, but it held steady with heavy load in it so I then started rechecking everything. After checking everything for tightness I started popping off all the quick disconnect couplings. Third one I checked was the culprit. I had changed some out for normal wear leaks and used some I had picked up at a local TSC. I'll be changing them again with something a little better. Apparently it is not staying pushed in enough to let a full flow through it. It even had rust on the balls inside of it. Changed it out and now the bucket lifts quickly and is tilting a full load back much better. The BH isn't on it right now, so I will check it at a latter time.

And thanks, Dave! Now there is even more stuff I need to buy for my tractor! I'm ordering the forks and pressure checker kit and may even get the sprayer since the one I made is kind of a pain to put on and take off. I would get the bucket extender, but mine is so bent-up I doubt it would mount up right now!

Thanks again and really appreciate you guys taking the time to help me out...Stephen
 
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