Bleeding top and tilt on L2501 with L8372 Top and Tilt

[shaymus]

Is there a way to bleed the top and tilt cylinders? I have a L2501 with the L8372 Top and Tilt and 3 spool control valve. Both the top and tilt cylinders are very springy and mushy and they both leak down quite a bit.

No luck finding any info on Kubota's site or otherwise.

Any info would be appreciated.

 

[MtnViewRanch]

Fully extend and retract the rods 10-20 times. This will get the air out of the cylinders. As far as drifting, good luck, Kubota as well as some other brands of control valves seem to have drifting issues at least 50% of the time.

 

[old and tired]

It will self purge... Do you have a "double acting pilot valve" on the top and side links?

Double acting pilot valve, will stop drifting since it will only allow fluid to move after a certain pressure mark. Hydraulic fluid will move after 900* psi is applied. ( * = Wild guessing at the actual pressure needed to move.)

 

[shaymus]

A bunch of cycling the cylinders has helped with the air and sponginess. My prior hydraulic experience is limited to brakes and clutches. Will keep at it. I'm still getting a lot of leak down.

 

[shaymus]

It will self purge... Do you have a "double acting pilot valve" on the top and side links?

Double acting pilot valve, will stop drifting since it will only allow fluid to move after a certain pressure mark. Hydraulic fluid will move after 900* psi is applied. ( * = Wild guessing at the actual pressure needed to move.)

I will look into this. I don't have any documentation on the top and tilt, and there is nothing on Kubota's website. I may call them, but not sure how useful that will be. I also put in a call to the local dealer and am waiting to hear back.

Are these pilot valves something I can swap in? Any chance you have a link to something that worked for you? I'll keep searching and appreciate the info.

 

[TheOldHokie]

A bunch of cycling the cylinders has helped with the air and sponginess. My prior hydraulic experience is limited to brakes and clutches. Will keep at it. I'm still getting a lot of leak down.

Your leak down is not from air. Hydraulic oil is flowing out of the cylinder by one or more paths.

Dan

 

[TheOldHokie]

I will look into this. I don't have any documentation on the top and tilt, and there is nothing on Kubota's website. I may call them, but not sure how useful that will be. I also put in a call to the local dealer and am waiting to hear back.

Are these pilot valves something I can swap in? Any chance you have a link to something that worked for you? I'll keep searching and appreciate the info.

A DPOCV goes in the two lines between the valve and cylinder. They have four ports - two in and two out - and are commonly mounted directly on the ports on the cylinder but that can be hard to DIY. You can put them anywhere in the run and they will work equally well.

Dan

https://summit-hydraulics.com/produ...ted-hydraulic-check-valve-6-sae-ports-11-gpm/

 

[TheOldHokie]

Look at the following link, do the tests and you see for sure where your issue is.

Top & Tilt Cylinder Test Instructions

Succinct and to the point

Dan

 

[shaymus]

Look at the following link, do the tests and you see for sure where your issue is.

Top & Tilt Cylinder Test Instructions

Thank you for this link! It looks like a simple and logical way to test, with some fixes as well.

 

[Runs With Scissors]

but that can be hard to DIY.

Shaymus, this is the understatement of the century.

Unless you are some sort of hydraulics Guru; Listen to Dan and put them inline using hoses, or just buy new cylinders with the check valves already installed.

Here is my story, I haven't updated it yet because I am/was waiting on back ordered parts.

https://www.orangetractortalks.com/...-on-how-to-shoot-ones-self-in-the-foot.63695/


Paul

 

[shaymus]

Whaaaah, my top and tilt cylinders are sagging... says the noob (that would be me).

Turns out to be more complicated and nuanced than initially thought. It usually is.

Cycling the top and tilt pistons like a mad person has helped a lot. The sponginess is gone. But... I still get the leak down and I'll admit it that it drives me nuts. I feel like things should stay where I put them for at least enough time to actually do some work.

The way things are now, in about 8 or 10 minutes, the top and/or tilt cylinders still leak down so much to the point that stuff gets messed up and I don't realize it for a while because I'm trying not to run over things, not hit things, adjust for hills and valleys, etc. I mean, that's why I bought it (or bought into the marketing)! If it's not reasonable for it to be useful, then I want to know, and I'd rather deal with turning turnbuckles if that is more productive and practical.

That said, I will keep at it and hopefully figure out the next things to try to make it work. I'm hopeful that it will be worth it in the long run.

 

[MtnViewRanch]

Whaaaah, my top and tilt cylinders are sagging... says the noob (that would be me).

Turns out to be more complicated and nuanced than initially thought. It usually is.

Cycling the top and tilt pistons like a mad person has helped a lot. The sponginess is gone. But... I still get the leak down and I'll admit it that it drives me nuts. I feel like things should stay where I put them for at least enough time to actually do some work.

The way things are now, in about 8 or 10 minutes, the top and/or tilt cylinders still leak down so much to the point that stuff gets messed up and I don't realize it for a while because I'm trying not to run over things, not hit things, adjust for hills and valleys, etc. I mean, that's why I bought it (or bought into the marketing)! If it's not reasonable for it to be useful, then I want to know, and I'd rather deal with turning turnbuckles if that is more productive and practical.

That said, I will keep at it and hopefully figure out the next things to try to make it work. I'm hopeful that it will be worth it in the long run.

Well, unfortunately, it sounds as though the control valves are faulty. What is even worse than that, Kubota will do nothing about it. "Just how it is" is Kubota's std answer.

There are solutions, and not really even that costly. Having these adjustments at your fingertips is absolutely worth every penny that you have-will have invested in these if you plan on doing any grading at all IMO.

If you want to fix this, decide which solution provided is going to work best for your applications.
My guess, get the check valves if you are new to all of this.

 

[TheOldHokie]

Whaaaah, my top and tilt cylinders are sagging... says the noob (that would be me).

Turns out to be more complicated and nuanced than initially thought. It usually is.

Cycling the top and tilt pistons like a mad person has helped a lot. The sponginess is gone. But... I still get the leak down and I'll admit it that it drives me nuts. I feel like things should stay where I put them for at least enough time to actually do some work.

The way things are now, in about 8 or 10 minutes, the top and/or tilt cylinders still leak down so much to the point that stuff gets messed up and I don't realize it for a while because I'm trying not to run over things, not hit things, adjust for hills and valleys, etc. I mean, that's why I bought it (or bought into the marketing)! If it's not reasonable for it to be useful, then I want to know, and I'd rather deal with turning turnbuckles if that is more productive and practical.

That said, I will keep at it and hopefully figure out the next things to try to make it work. I'm hopeful that it will be worth it in the long run.

Put one of these in each circuit. That's $150 delivered plus the cost of four short hoses and a few fittings. You will lose float but stop the leakdown.

Dan

Double Pilot Operated Hydraulic Check Valve, #6 SAE Ports, 11 GPM

Double Pilot Operated Hydraulic Check Valve, #6 SAE Ports, 11 GPM Free Shipping

summit-hydraulics.com