Strange hydraulic problem

   / Strange hydraulic problem #1  

dnw64

Veteran Member
Joined
Feb 13, 2017
Messages
1,491
Location
Southeastern Vermont
Tractor
Kubota B3030 Cab
On my Kubota B3030 with front snowblower & hydraulic chute rotation.

Hooked hydraulics up according to color coding (this is new to me this year). Rotates left but not right. Trying to turn right, you can see the hose jump a little bit as if it's getting pressurized.

Swapped lines (at the valve). Now will turn right, but not left. This suggests that the hoses are not plugged and the motor is functional in both directions.

Then, swapped up/down and rotation lines at the valve. Now it goes up and down using the curl/uncurl function, and turns left/right with up/down function.

Perplexed...
 
   / Strange hydraulic problem #2  
On my Kubota B3030 with front snowblower & hydraulic chute rotation.

Hooked hydraulics up according to color coding (this is new to me this year). Rotates left but not right. Trying to turn right, you can see the hose jump a little bit as if it's getting pressurized.

Swapped lines (at the valve). Now will turn right, but not left. This suggests that the hoses are not plugged and the motor is functional in both directions.

Then, swapped up/down and rotation lines at the valve. Now it goes up and down using the curl/uncurl function, and turns left/right with up/down function.

Perplexed...

That would be the expected operation with a spool valve with rapid dump feature. Great for a loader bucket function, not so good for chute rotation.
When hooked up "the other way", the heavy blower "looks like" a bucket and so lowers. Perhaps a bit rapidly.
 
   / Strange hydraulic problem
  • Thread Starter
#3  
That would be the expected operation with a spool valve with rapid dump feature. Great for a loader bucket function, not so good for chute rotation.

I don't quite get it. Bucket dumps even when empty. Also, will lift front of tractor if bottom of bucket is flat on ground and un-curled...?? Then again, hydraulics are not my specialty.
 
   / Strange hydraulic problem #4  
Push harder to the right. I had the same issue when I added the front blower to my B3200.
 
   / Strange hydraulic problem #5  
I don't quite get it. Bucket dumps even when empty. Also, will lift front of tractor if bottom of bucket is flat on ground and un-curled...?? Then again, hydraulics are not my specialty.
It sends pressuerized hydraulic fluid to both the rod and base ends of the cylinder. The volume difference caused by the rod means that it will extend, the fact that both sides are connected means that the fluid will leave the rod end and enter the base end causing it to dump faster than would be otherwise possible. This is also known as "regen mode".
The hydraulic motor for the chute rotation does not have a displacement difference, so it just sits there.
You need to see if your loader has a place that is not "regen" (usually you move the loader control a little bit to the right instead of all the way to the right).

Aaron Z
 
   / Strange hydraulic problem
  • Thread Starter
#6  
Push harder to the right. I had the same issue when I added the front blower to my B3200.

We have a winner!

It's sorta like the float position (except it doesn't stay there). Not sure why, and it will take a bit to get used to, but it works! Thanks!

On a related note, that chute rotates awfully fast! Great if you want to change direction quickly, but it will be really hard to fine-tune it...
 
   / Strange hydraulic problem #7  
On a related note, that chute rotates awfully fast! Great if you want to change direction quickly, but it will be really hard to fine-tune it...

If you want to slow it down, you can add in line orifice fittings between the hose and coupler on the chute lines, the smaller the hole the slower it will rotate.

** Link for example only, not an endorsement of seller.
Parker XHX7 Orifice | In-Line Orifice Connectors

Buying tip - if you get one that's too small (too slow) you can always drill it out. If you get one too big (too fast) you have to send it back. ;)
 
   / Strange hydraulic problem
  • Thread Starter
#8  
If you want to slow it down, you can add in line orifice fittings...

Great idea. Thanks!

Now I just have to guess at what size I might need/want...
 
   / Strange hydraulic problem #9  
aczlan, This sounds very similar to the symptom i'm having with a power angle snow plow setup I fab'd; I added a old plow with two new single acting angle rams/hoses; I purchased a 12V hydraulic diverter valve (Idaho Implements - Universal Third Function Diverter Valve Hydraulic Kit, Less Hoses ) that someone else recommended on one of the forums for same purpose to use on my Kubota B7500HST w/LA272 loaders bucket curl circuit; my expectation was that when i activate the diverter solenoid switch for the valve ports connected to the power angle rams, left stick would angle left and right stick would angle right. But it only would angle left not right; curl function in an out still worked normally from the diverter valve ports for that; swapped plow angle hoses and then would angle right but not left, confirming no problem with hoses/fittings/rams. Then swapped ports in the diverter valve (ports for curl function now connected to angle ram hoses and vice versa) and curl still works correctly but angle only goes one direction, which eliminates the diverter valve being the problem. so is this caused because bucket curl has double acting cylinders? and plow angle rams are single acting? and the "regen" is causing this? I figured since one ram is always pushing, the other ram would be collapsing, just like double-acting; I think I already tried different positions on the joystick to see if that made a difference; I see you have a B7500HST; do you know if this loader SCV should have this ability? Any ideas??
 
   / Strange hydraulic problem #10  

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