3pt hitch issue any ideas

[ericher69]

Hook up the 60" box blade (450lbs) to the b2920. No issues; park overnight.

Next day raise the BB and it will not lower!

Checked the 3pt hitch open/close valve between legs is fully open. Will go up but not down.

Here is the strange part. If I shut off engine and try to raise then lower the bb it will until next time I fully raise it. Need to shut off again and start over.

Any ideas?

Thanks

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[ericher69]

Anyone??

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[boggen]

not a clue about your specific tractor....
TractorData.com Kubota B2920 tractor information

the 3pt hitch valve and piston/cylinder setup tends to be all built directly into the rear end of majority of tractors. so most likely means seat removal and getting into the ugly areas to get to this or that.

have you double checked all your fluid levels? engine oil, hyd oil up in front near engine, then transmission/rear end hyd/transmission oil?. possibly 3pt hitch runs off transmission or rear end vs hyd pump that runs FEL (front end loader) or rear remote hyd ports.

wondering if there is a check valve or pressure relief valve some place in the rear end that is sticking or valve issue.

illistrated parts on kubota site seems to be down at least for me.
https://www.kubota.com/part/partsList.aspx

 

[Mendonsy]

I think boggen is on the right track on this. Sound like the pressure relief trips when the hitch reaches the top of the travel and can't reset itself with the weight on the hitch.
Does it do that when the box blade is not attached??
Does dropping the box blade all the way down do anything??
Does your hitch have an upper stop??
On my B7500 there is a spring arrangement that releases the lift lever when the hitch gets near the top. It doesn't work all that well, but better than nothing.

 

[ericher69]

I think boggen is on the right track on this. Sound like the pressure relief trips when the hitch reaches the top of the travel and can't reset itself with the weight on the hitch. Does it do that when the box blade is not attached?? Does dropping the box blade all the way down do anything?? Does your hitch have an upper stop?? On my B7500 there is a spring arrangement that releases the lift lever when the hitch gets near the top. It doesn't work all that well, but better than nothing.

Yes I did notice the relief valve tripping as the 3pt reaches the top. I need to manually move the lever down as the RPM's drop when I hear the relief activate.

Then it does not lower.

The 3pt lowered fine when attaching the bb as there was no weight on it.

I did check all fluid levels before starting the tractor.

Will check the stop adjustment at the top to see if this may be the issue.

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[s219]

Try adjusting (or greasing) the return link that should bounce the lever back to neutral when you hit the top. It's attached to the 3-pt mechanism and simply bumps the lever to neutral. That should happen long before you cause the relief valve to kick in.

 

[ericher69]

Try adjusting (or greasing) the return link that should bounce the lever back to neutral when you hit the top. It's attached to the 3-pt mechanism and simply bumps the lever to neutral. That should happen long before you cause the relief valve to kick in.

Any pictures of said return link?

Will look at it this afternoon. Pretty hard to see what is what since I have a sims cab installed.

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[Mendonsy]

Here's a picture of the linkage on my B7500. The B2920 is a lot newer tractor so it's probably a bit different.
The link attaches to the bottom of the 3 point lever and goes through a swivel on the right side lift arm.
The spring end (nearest) controls the up limit and is adjusted by the two nuts. The sliding stop adjusts the down limit.
The swivel moves with the lift arm and pulls the linkage when either stop is reached.

 

[ericher69]

Here's a picture of the linkage on my B7500. The B2920 is a lot newer tractor so it's probably a bit different. The link attaches to the bottom of the 3 point lever and goes through a swivel on the right side lift arm. The spring end (nearest) controls the up limit and is adjusted by the two nuts. The sliding stop adjusts the down limit. The swivel moves with the lift arm and pulls the linkage when either stop is reached.

No it's pretty much identical.

I played with the lever stops today seems they where way out of adjustment.

Seems to have helped will check your suggestion hopefully tomorrow

Thanks

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[Mendonsy]

My up limit was off quite a bit when I got the tractor. I had to adjust the two nuts to get it to work correctly (sorta).
The down limit is way off but I just left it that way. If you set the down limit too high and the lift leaks down while the tractor is shut off it will actually force the lever back and try to raise the lift as soon as you start it.