B2100 3pt jumping in draft position.

[jward]

Hello everybody,
First wanted to thank you guys for all of the knowledge shared on this site. I am a long time tractor lover of all kinds. Ran into something I never have before. I've got a 96 b2100 HST I bought a few years ago to do my yard work with. Not sure the previous owner took as good of care of the internals as he did the outside. I changed the hydraulic fluid and filter the other day, and now the 3pt lifts fine, but at stopped height, with any weight on it, it hops up and down shaking the whole tractor. I thought it might be air, so I mowed with it and got it warm thinkin is bleed it out, but it hasn't. I retraced, out new orings in the supply line ( strainer) to the punp and sprayed all fittings down to check for leakage. If I knew how to upload video I'd show you what I mean. Thanks for reading and I'd appreciate any feedback. It was not doin this before I changed the fluid.

 

[dmanlyr]

What fluid did you use?

David

 

[jward]

I used the super UDT they say to use.

 

[ShaunRH]

In an 'open' system air should self bleed relatively quickly after working the unit. It's possible the dirt in or viscosity of the old fluid was letting a leak seal while new 'super' fluid is fine enough to leak past seals that the old fluid couldn't. This is common when switching from dino to synthetic oils in a lot of vehicles/equipment.

I'd run the 3pt a lot, up down up down until you're sick of it. Also run the HST a while. That should work out any possible air. Check for leaks. If no leaks, and still doing it, you likely need a 3pt hydraulic rebuild. The old oil was probably masking an issue with them. Had this happen in my old orange iron tractor.

 

[jward]

That's kinda what I was leanin toward. I didn't want to tear the housing off till I had been over every option. Doesn't look like it'll be to hard to rebuild the control valve. Thanks for your help.

 

[North Idaho Wolfman]

What you are describing is called hunting, it can be caused by a valve problem, air, or maladjustment of linkage.
Since it started with a filter and fluid change I'm going with air is getting sucked in.
Run it for a while and check the fluid, is it foamy?
If it is it's pulling in air from somewhere, look at all fittings and hoses on the large suction side of things.

Try running it and see if it does the same hunting when the three point is lifted 3/4 of the way up?
Does your lever move with the action of the three point, like the more you move the lever the more the three point moves or is the lever spring loaded to go to center and you push up or down and lever returns to center?

 

[jward]

It hunts at any height only when weight is applied. Even at the lowest point when I step on the arms it hunts. When you look down thru the fill hole it doesn't look excessively foamy. When you lower it the oil stream looks clean.

 

[hodge]

Describe excessively foamy. Before the change, had you looked at the oil right after operation? Was there any foam then?
Have you checked your filter to make sure it is seated and sealed? Did the old oil seal come off with the filter, or could it still be stuck on and not sealing properly? Retrace your steps- it is likely related to the filter and fluid change.

 

[jward]

Filter is right with only new seal in it. When you look down in the fill hole with the hitch down the oil stream coming out of the control valve is clean oil. When I raise it nothing comes out then at draft you can hear it swishing while it jumps up and down and it foams up from the turbulence that's the only time it gets foamy. Not when fresh oil is flowing thru in the down position.

 

[North Idaho Wolfman]

Sounds like the draft control feed back is out of adjustment.
I'll look and see if I can find anything else tomorrow.

 

[dukunter]

Sorry to jump on this a year later, but I'm having the exact same issue with my L5240. Any resolution on this?