FEL curl dump stops working with heavy use

txndncowboy · Feb 4, 2020

Don't know if you folks can help because my problem isn't a compact or sub compact tractor, I don't think. It's a Kubota 9540(edited to correct size), I think there's an M in front but can't remember. The loader works fine and I can curl and dump until I've got it hot from, from fast quick use, then suddenly after dump it won't curl or visa versa, just depends on when it wants to do, but it stops working. I've figured out that if I give it quick pulses of curl/dump that after a bit it will start working again. Almost like it has air in the lines somewhere. But I thought that if there was air it would self bleed after numerous uses and shut downs.

There have not been any disconnects of anything on the FEL but of course several off the auxiliary ports for other equipment. One in particular is a hydraulic driven side cutter I use and it has never had a single hesitation let alone full stop. It just keeps on working thanks to a little retainer I made to keep a lever pulled. But this bucket problem has bugged me since I got this machine, used, maybe second owner but might be third. I noted two large filters that I'm assuming are hydraulic filters. Could one of those be causing this or do you have any other suggestions of cause?

Again, I know this size tractor may be out of your range but I'm scratching my head so thought I give this a try. I'm slow at this so may not see any replies as I'm still looking for anything that shows signs of fluid leaking which could mean air entering but so far, nothing. Just as clean as the day it was delivered. Minus the mud I've got on it.

EDIT:
Oh crap, I stated the wrong size tractor I have. I've been reading problems and 5400 was in my head. Found several search hits about a 5400 for some reason. But I have a 9540. Does that make a big difference in diagnosis? And sorry about that. That's what I get for trying to use the search function and find an answer. It's now corrected above too.

RNeumann · Feb 4, 2020

Sounds like you have a curl cylinder seal that is failing. The warmer the fluid the worse it gets. Cylinders are fairly easy to rebuild. Their are several videos on YouTube. Otherwise a hydraulic shop should have you up and running fairly quickly.
Their is debate about just doing both cylinders or diagnosing which one is bad.

txndncowboy · Feb 4, 2020

Guess I can prove that's the cause by swapping the curls for the up and down and see if it follows or stays with the curls. I have a set of 4 foot extensions I can use if not enough slack to do a direct swap at the cluster where everything is connected.

EDIT:
Oh crap, I stated the wrong size tractor I have. I've been reading problems and 5400 was in my head. I have a 9540. Does that make a big difference in diagnosis?

RNeumann · Feb 4, 2020

Switching the “up and down” won’t diagnose a bad cylinder.

Disconnect and plug the hoses of one of the cylinders. Leave the other cylinder uncapped (it’s gunna leak fluid) or remove it from the FEL.

Bypass testing a hydraulic cylinder - YouTube

txndncowboy · Feb 5, 2020

After watching the video, it would appear in order to test your suspicion, I need to completely disconnect one cylinder and one side of the other since it has 2 cylinders. Actually I already know they are leaking though since I can have the bucket level when I shut down for the day and by morning I can see the bucket already dropping down. So both cylinders must need to be fixed.

rScotty · Feb 5, 2020

txndncowboy said:
After watching the video, it would appear in order to test your suspicion, I need to completely disconnect one cylinder and one side of the other since it has 2 cylinders. Actually I already know they are leaking though since I can have the bucket level when I shut down for the day and by morning I can see the bucket already dropping down. So both cylinders must need to be fixed.

That much bucket droop overnight isn't unusual. I wouldn't just run out and rebuild the cylinders on that account.
If you have a service manual it will say how many inches/hour of droop is acceptable. I'll bet you'll find it can be a lot more than you have.

Yes, both of those large filters are most probably hydraulic filters. That's where I would start. Plugged filters can definitely cause heat problems.
So if it were mine, I'd go with get some OEM filters and replace them.
And since you are the second or third owner you probably don't know what it has in there for hydraulic oil. There's a lot of cheap hydraulic oil available because 15 gallons of the good hydraulic oil is costly..... and hydraulic filters aren't cheap either.
But until you do those things you don't really know what you've got to work with.
rScotty