LA211 FEL Dump Power issue

[kiltedpiper98]

Howdy, thanks for all the great info on the forums (replies etc). I have a BX2200 with a LA211 Loader. It has served me well for quite a few years. Recently I had to replace quite a few hoses as they all went bad together (about 14 years old). After replacing them, everything worked fine, except I did not have power in the dump (uncurl) direction. It will dump slowly using gravity, but I cannot pickup the front end of the tractor any more (unless I drop the bucket to 90 deg to ground and use the lift arms entirely. I cannot grade or dig with this issue. Sometimes when I move the lever all the way to the right (power dump) it curls instead of dumps. I have swapped the loader arms up/down with the curl/dump hoses, and all the functions work except for dump (same problem). I swapped the QD's on the curl and dump (blue and red) lines, didn't fix it. I do hear a squeal when trying to dump (similar sound to when the mower lift level is up and I try to use the bucket. I have not pulled the pressure relief valve (I believe it is under the mower PTO attachment). Is that my next step, or is the curl/dump cylinder bad. Thanks for your help!

 

[Harry in Ky]

The relief valve is not the problem. If it were, then all functions would be affected. Since you've swapped the valve spools with no improvement, you're down to the bucket curl circuit. Possibly one of the newly replaced hoses has something blocking flow internally, two of the hoses are crossed, or maybe there's some sort of mechanical bind. Something is causing the relief to open when this circuit is activated, and the flow through the cylinders is somehow restricted. You might check the quick couplers again, and maybe swap them between circuits to see what happens.

 

[Grandad4]

What he said! Was just composing essentially the same reply and noticed Harry's comment. Also, if the loader worked OK before you changed the hoses and is only now malfunctioning, it's unlikely the curl cylinder just happened to fail right when you were changing the hoses. I'm no hydraulics guru (there is a "Hydraulics" subforum here, where you may get a real "guru's" advice!), but how long did you run it after doing the hoses? If air got into the circuit during the change, it might take a few minutes running to get the air purged.

 

[kiltedpiper98]

Thanks y'all. A few pointed questions:
1) Should I swap this to the hydraulics forum?
2) If swapping to new QD's doesn't work to test for blockage which should I do:
a) Disconnect a line and blow air through it
b) Disconnect one line at the cylinder (most likely the extend circuit) and use the tractor hyd system to shoot hyd fluid through it (sounds like a mess with high pressure)

Longer version with back-up info:
I probably have about 15 hours on it since swapping the hoses, so I would think the air has made its way out. That was my initial thought when it first started. As for checking the lines, is my best bet to disconnect them, let the oil drain out, and try to blow compressed air through them to verify there is not a blockage? I did not try to swap the QDs with another circuit, only within this circuit. I think I will buy a new QD to make that process quicker. I was thinking that maybe I should try to switch the lines at the cylinder to see if that switched the problem (ie cant curl well, but can dump). IIRC, the curl is more powerful than the dump (retract vs extend), and if I swap the lines the cylinder should function correctly in the dump direction, and have a hard time in the curl direction. It should be that the line closest to the bucket on the cylinder is the curl line and the closest to the tractor is the dump (extend) circuit. As these two are tied together (one line is returning), I guess that a blockage of sorts in one line, may affect the operation.

Thanks!

 

[davesl708]

I had a similar issue that was related to dirty oil when I first bought my BX. Crud in the oil collected on the spindle blocking fluid flow to the lift cylinders.

By chance did you use Teflon tape on the connections? Could it be possible tape or thread lock got into the lines and is stuck in the valve?

 

[kiltedpiper98]

Possible dirty oil is one challenge, and teflon tape running amuck is a possibility as well. DvesI708, What did you do to clean out your lines?

 

[davesl708]

Possible dirty oil is one challenge, and teflon tape running amuck is a possibility as well. DvesI708, What did you do to clean out your lines?

I had to flush the system twice with cheap fluid and tear the valve down and clean it out. Replaced the orings and gaskets while I had it apart.
A new tank of SUDT2 and it has been trouble free. I have put about two hundred hours on it since and no more problems.

 

[kiltedpiper98]

Ouch sounds fairly intensive. To flush, did you just drain the system, change the filter, fill, run for a while, dump, change the filter, run for a while, dump, change the filter, and fill with good fluid?

 

[davesl708]

Yes. Used UDT to flush and new filter with SUDT2.
The valve assembly is not complicated just make sure you get the spindles back in the same way.
You can wait on the valve till after the flush and see if that clears the problem,

Look at the oil first. If it is black and thicker than normal then flush it. I don't know the maintenance history of your tractor but the guy I bought mine from had not changed the fluid in the five years he had it. It looked like it had never been changed.
The filter was still Kubota gray.

 

[kiltedpiper98]

So I bought two couplers to swap out with the QDs to check if the QDs were bad. No change. I then disconnected the hose from the extend side of the cylinder (closest to the tractor) and tried to blow compressed air through the line. No luck. I think disconnected hoses all the way up until I isolated one hose that would not allow air to pass. It was one of the ones that I replaced recently. So back to the hyd hose facility to have them replace that line. I will post if the results are positive.
Thanks.