Draft control bleed off

[blenderbender]

I have a Kubota B3000 w/draft control but when fully closed to maintain implement height whatever implement is hanging back there drifts down within several or so minutes. I'm assuming this is a valve/hydraulic issue of some sort , or do I have the absolutely wrong idea what draft control is used for? If anyone has any suggestions as to what to remedy this I'd really appreciate the feedback. Thanks!

 

[workinonit]

Draft control senses pressure on the toplink and makes the necessary adjustments to the rockshaft to maintain a constant depth when running ground engaging implements. I use it religiously when I'm running a box blade or my landplane. It keeps them from loading up and helps to distribute material from the high to low places.

 

[blenderbender]

After I posted and read up more on draft control I realized that maintaining implement height doesn't appear to be it's purpose. I should have stated that I did try using the 3 point hitch lift to accomplish this but the lever vibrates and eventually lets the implement drift down. The locking feature doesn't seem to hold well. I do use the draft control to regulate the speed of an implement when I drop it and realized if I shut it completely that the implement will not drop at all. So I figured that would maintain a desired height of the flail mower in this case.... except that it too drifts down.

 

[oldnslo]

Sounds like You are using the rate drop control valve vs draft control. Rate drop will lock implement in raised position and regulate how fast the implement lowers.

 

[blenderbender]

Sounds like You are using the rate drop control valve vs draft control. Rate drop will lock implement in raised position and regulate how fast the implement lowers.

You could be right, I'll have to look in my manual, but I thought that was the draft control knob . However it still does not lock in the raised position (for long anyway), therein lies my problem.... thanks!

 

[5030]

I wasn't aware that the smaller, non utility-ag Kubota's could be had with draft control. Draft control on a Kubota will always be a second lever next to the raise and lower implement lever and it's easy to tell if your unit has draft control besides the second lever, the business end (back end of the tractor will have a greaseable assembly with at least 3 through holes in the forging so you can adjust how sensitave the draft actuation is, plus there will be additional linkage attached to the forging that telegraphs that movement to the valving. When I don't need it, I keep the draft control lever all the way forward which negates it's effect. I believe all Kubota's have a lowering speed control usually placed below the seat but that only controls the 3PH lower speed and it has nothing to do with draft control at all.

 

[blenderbender]

You're most likely correct, the knob I always thought was for draft control is near the floor below the seat. The lever next to the 3 point lever is cruise control. I'll need to look at the back end and I'm guessing I do not have any draft control function. Still need to figure out how to keep the 3 point from drifting down on me.

 

[5030]

The knob below the seat acts on a needle valve in the rockshaft assembly and closing it will eliminate any drop.

 

[blenderbender]

The knob below the seat acts on a needle valve in the rockshaft assembly and closing it will eliminate any drop.

But it doesn't..... it drifts down.

 

[ptsg]

But it doesn't..... it drifts down.

If it still drifts down with the knob fully closed, then the seals on the piston for the 3 pt lift cylinder are bad.