Hydr only working 1-way after implement change

[SeanInMN]

Ok, I'm a little perplexed with a hydraulics problem, and I'm betting someone here will tell me what I'm doing wrong.

Kubota L3130, switching from FEL to Front Blade. I have the normal 4-position valve for the FEL (fwd = down, back = up, left = rollback, right = dump). I took off the FEL and installed Kubota front blade, which hooks to a subframe. Up/Down on the blade works the same as for the FEL. And left/right on the joystick should be left/right angle on the blade.

My problem is that when I first hooked up the blade, I was able to angle left, but not right. When I switched the hoses at the valve, I was able to angle right, but not left. (Blade hydraulic setup is drawn in attached image).

When I first hooked up the hoses, and could only move in one direction, I figured that one of the quick attach connectors wasn't seated properly. But everything seemed seated properly, and the same valve port seems to fail when I swapped hoses (i.e. the blade could then move the other direction).

Am I right in thinking that since I can move either left or right, by switching hoses, the actuators themselves are fine? It seems like one of the ports on the valve is not working. But up/down on the FEL bucket worked fine before disconnecting FEL hoses. Do the quick attach connections easily get jammed up somehow? Any other thoughts, or things that I should check (I should probably switch back to hydraulics on the FEL, just to verify that all four ports on the valve are still working).

Thanks in advance for the help!

Sean

 

[SeanInMN]

Here's the drawing of hydraulics for the FEL. So the difference is that FEL has actuators in parallel, so they move together, and blade has them in series, opposed, so they move opposite to each other.

Sean

 

[JerryG]

Sean,
Have you used the blade before? If you haven't, you may need to bleed the line between the cylinders. Do this while you are extending one of the cylinders. That should take care of your problem. You don't have to do this on the loader, because they are self bleeding. With the cylinders like they are on your blade, they are not.

 

[snowman]

Are you sure that the hoses are attached to the right connections?

My FEL (LA302 - B7500) has four quick connects. There've been times that I've hooked them up wrong when putting the FEL back on. When that happens, the FEL won't respond properly (moving up or down, or curl). Just play around with the connections.

 

[SeanInMN]

No, I've not used the blade before, so perhaps I need to bleed first. Does this still make sense, given that I can switch hoses at the valve, and the opposite direction then works? To me, this made it seem like it's not the case that there is air in one of the hoses or pistons. Also, my dealer did have the blade hooked up and said that he verified operation of all hydraulics. But I never verified operation while it was still at the dealer, so maybe he didn't really check everything out.

Regarding having the hoses hooked up right, I did switch the hoses--and then instead of just moving in one direction, I can just move in the other direction. I did verify that up/down are connected to the proper ports, compared to FEL--and up/down work just fine on the blade. So the only hose-switching option seems to be swapping the other two.

Sean

 

[jimgerken]

That problem sure sounds familiar to one I had. The boom would move but slowly, and only to a point. I switched the hoses around and somehow switched them wrong again! It was actually the day I decided to take it in for service that I looked close enough to see my mistake. Assume nothing, remove them all, start over, connect carefully. Then, MARK THEM BETTER WITH COLORED ZIP TIES! /forums/images/graemlins/blush.gif

 

[JerryG]

<font color="blue"> No, I've not used the blade before, so perhaps I need to bleed first. Does this still make sense, given that I can switch hoses at the valve, and the opposite direction then works? </font>
Yes, it does. I would bleed the hose between the cylinders.

 

[Henro]

<font color="blue"> My problem is that when I first hooked up the blade, I was able to angle left, but not right. When I switched the hoses at the valve, I was able to angle right, but not left. </font>

The fact that by switching the hoses you were able to move the blade in either direction proves that the problem is not in the hydraulic cylinders, but rather in the connections at the valve (or the valve itself, but that is unlikely).

If the problem was the cylinders or how they were connected, then when reversing the hoses at the loader valve, you would not see any movement it the opposite direction. Since by reversing the hoses you are able to change direction of movement of the blade, you have almost certainly proven that the control valve is not supplying flow in both directions.

Check the hook up at the control valve. IF the loader works properly, but the blade doesn't...it must be that you have the lines hooked to the wrong place on the loader valve.

Worst case, put the loader back on and verify which pair of outlets are for lift, and for curl of the bucket...

I don't know anything about your snow blade, but I do know that if swapping the hoses causes the movement of the blade to reverse, the problem is unlikely to be with the cylinders or the connection between them.

edit: Would not hurt to verify the hook up beween the cylinders as well. Just to be sure they are not bucking...and never assume anything is like you think it is...verify, and verify again...if I had a nickle for every time I have said "man, why didn't I notice that" I would have a full piggy bank easily... /forums/images/graemlins/blush.gif

 

[rambler]

</font><font color="blue" class="small">( <font color="blue"> No, I've not used the blade before, so perhaps I need to bleed first. Does this still make sense, given that I can switch hoses at the valve, and the opposite direction then works? </font>
Yes, it does. I would bleed the hose between the cylinders. )</font>

Assuming it really did work at the dealer, then this should already be taken care of.

But, it sure sounds like this is the problem - air between the 2 cylinders. It will be difficult to bleed if you look at it - oil never does get there from the tractor!

Either the cylinders & hose in the middle were never filled with oil, or you have the quick connects hooked up wrong. Going to be one fo those 2 things.

Now, as others say, are you sure you got the hoses right? The blade likely will drop on it's own weight if you hooked it up wrong. So you power it up, & it puts itself down even if the hoses are wrong....

Also, do you have 'float' option in there somewhere - you need power to swing side to side, not float.

--->Paul

 

[DK45C_Dave]

If the cylinders are sequenced (slightly different sizes, hardly noticeable), they could be connect backwards.?