LA211 Operates Slowly up & down

[POswego]

New to the site.

I have a BX2200 with a LA211 FEL and the up/down (boom cylinders) is very slow last couple uses, but the curl of the bucket seems normal. I don't see any leaks anywhere on the FEL lines and all the quick connects seem fine. Is it possible that the boom cylinder lines could have air in them; if yes, do I need to manually bleed the lines to the boom cylinder? Is it possible that the boom cylinders are bad/warped, etc and that would effect the up/down movement. I have owned the tractor new since 2004. I'm hoping it is not the control valve as I have read they are expensive to replace/fix. I have never used my rear PTO and my undermount mower deck works normal.

Any recommendations would be greatly appreciated - thanks in advance.

 

[junkyardwarrior]

Make sure your lift lever (for your mowing deck) is in the neutral position. If in the "up" position, it will "steal" hydraulic power from the loader, in simple terms.

 

[gwdixon]

The hydraulic pump on these tractors is quite small. Pretty much only one function can be run at full power. (3PH, HST, boom cylinders, curl cylinders, and whatever else is hooked up to the pump) If the pump sounds like it is laboring then something is engaged that you are not aware of. Maybe the foot pedal is not centered or the 3PH is slightly lifting...things like that.

If you have recently removed / reinstalled the loader, unhook the quick attaches and reattach them. No bleeding is necessary. Just cycle the FEL controls and any air will be forced out.

The last thing that I can think of to try is to rev up the engine. Everything hydraulic works much faster. See if that helps.

Since it is only the boom that seems affected, my money is on the QA connections.

 

[TMGT]

With proper engine speed the loader should be capable of compound functions, also the HST is a separate system so pedal position shouldn't have any effect on the loader or 3pt function.

Because of the hydraulic systemdesign, engine speed is very important to operation. Every other suggestion has already been said.

 

[junkyardwarrior]

With proper engine speed the loader should be capable of compound functions, also the HST is a separate system so pedal position shouldn't have any effect on the loader or 3pt function.

Because of the hydraulic systemdesign, engine speed is very important to operation. Every other suggestion has already been said.

Correct. I'll add that even Kubota lists the hydraulic pump output to be rated at maximum engine speed, in other words, wide open. The pump is tiny, does not flow much (and cant because the system has a small hydraulic fluid capacity and would overheat quickly with a larger pump), so it depends on engine speed to make enough flow to work the loader. At idle, it barely moves the loader. Raise the RPM to 2500+ RPM and it comes to life. I know, some folks don't like the noise but that's the way Kubota designed the entire tractor, to be run at full throttle. It will run cooler, work faster, and last longer. But it makes a little more noise and that's the only downside. It's not like a dozer or track hoe )or even a larger Kubota) that moves enough hyd oil even at lower speeds to make the system work properly.

The HST has it's own little hydraulic pump....called a charge pump. It is totally separate from the main hydraulic pump. The only thing is shares is the oil, as it all runs off of oil that is in the sump (trans case) of the tractor. And because of it's small volume, it should be changed per the service manual's recommended hourly interval. This includes cleaning of the screen and replacing the filter. And use ONLY super UDT2 in them, especially if the back hoe is used a lot on the TLB BX's. Lot of guys don't like the price of UDT2, but it DOES work a lot better.

 

[TMGT]

Another thing about the BX hydraulic system is that it has a single pump for the steering and implements, meaning it should have a priority valve that provides a fixed amount of flow to the steering valve with any excess flow going to the 3pt and loader. At low engine speed/flow, almost all the pump volume is going to the steering system.

 

[gwdixon]

I don't doubt the facts of the BX hydraulic system outlined above.

However, practical operation has found this situation:

I'll drive into a pile of gravel with the HST in "low" and the revs up. If I keep the pedal down to maximize the load of gravel in the bucket, the FEL will not curl and the boom will not lift. If the HST pedal is then centered, the curl and lift function works, but with a bit of strain. And I have spread many yards of gravel.

Granted, a bucket full of gravel is quite a load on the system and it is likely nearly maxed out. Quite a bit of counterweight is required along with the loaded rear tires.

Anyway, my experience is that using the FEL with the HST engaged robs the FEL of lifting ability. There seems to be some relationship there.

 

[POswego]

Thanks for all the good suggestions. I always run my tractor Full throttle, so I can rule out engine speed. For the first time since owning, I noticed oil on the transfer case at the rear of the tractor and it appears as though it came out of the breather (black plastic grommit with a small red cap) that is on top of the trans axle above the fill opening for the UDT2 fluid? I cleaned the oil off the trans case and then had my daughter operate the bucket while I watched the transfer case to see if I could find and leaks and nothing? I will tinker with it later and let you know if I get it resolved, but thanks again for all your help. PS - should oil come out of that breather? I thought of something else, I used to get a small amount of oil leaking out of one of the boom cylinders and now no oil leaks from them?

 

[davesl708]

Thanks for all the good suggestions. I always run my tractor Full throttle, so I can rule out engine speed. For the first time since owning, I noticed oil on the transfer case at the rear of the tractor and it appears as though it came out of the breather (black plastic grommit with a small red cap) that is on top of the trans axle above the fill opening for the UDT2 fluid? I cleaned the oil off the trans case and then had my daughter operate the bucket while I watched the transfer case to see if I could find and leaks and nothing? I will tinker with it later and let you know if I get it resolved, but thanks again for all your help. PS - should oil come out of that breather? I thought of something else, I used to get a small amount of oil leaking out of one of the boom cylinders and now no oil leaks from them?

My BX had the same problem when I first acquired it. I bought it used. I found the hyd. fluid/filter had not be changed and plugged up the ports in the spindles in the control valve. Changing and flushing the system cured the problem.

Check the QD's first. Oil should not come out of the breather. Are you sure the oil level is correct?
Any chance the oil is contaminated.

 

[POswego]

Well the bucket finally operates properly. I could not move the lock/unlock lever back and forth (it was in the unlock position obviously), so I took the plastic cover off the joy stick/control valve, loosened the bolts on the joy stick and greased every moving part, it appears that the pin for the back and forth (up/down) position was slightly rusted/binding as was the lock/unlock lever. Unfortunately, I have to leave the tractor outside, but I will be covering the control valve from now on. Thanks for all your suggestions - I'm glad I found this web site.