Laser grading hydraulic valve issue.

[Complete Turf Care]

Voltage or hyd pressure.

There should be o-rings around the solenoid shaft going into the valve. They should be sufficient if there is no hyd spike.

The proportional valve works in relation to the signal it receives, could be large or small increments.

Is there a sensitivity adjustment on the valve or in the laser system.

There are adjustments on the laser system. One is for reaction time. I can increase or decrease the amount of time it will take to allow the system to change the blade height.

The other adjustment is to increase or decrease the 'dead zone' on the receiver. This will cause the blade to change height when it is more than the 'dead zone' off grade. I can set this to adjust the blade height at as little as 1/8" or as much as 2".

These adjustments are to avoid excessive movement of the blade (causing excessive heat). I will decrease the 'dead zone', and reduce the reaction time, as I get closer to finished grade.

However, I don't think either of these adjustments have anything to do with my 'coil' failure.

 

[J_J]

Did you say whether the failure was fluid pressure pushing past the o-rings or a cracked coil.

Are you using factory o-rings or just any o-ring.

If you remove the coil, can you manual push the center rod to push the spool rod in or out.

Can you see fluid leaking past the o-rings as you apply/cause pressure .

If the hyd pressure is exceeding the solenoid valve ratings, you might consider reducing the relief setting on the laser grader valve. If the grader does not have a relief valve, the remote valve should have one.

If you are getting large hyd spikes from the grader hyd system, a hyd gage might help you monitor and troubleshoot the hyd system.

 

[Complete Turf Care]

Did you say whether the failure was fluid pressure pushing past the o-rings or a cracked coil.
The failure doesn't seem to be o-rings, but something in the coil.
Are you using factory o-rings or just any o-ring.

If you remove the coil, can you manual push the center rod to push the spool rod in or out. I haven't tried this

Can you see fluid leaking past the o-rings as you apply/cause pressure .

If the hyd pressure is exceeding the solenoid valve ratings, you might consider reducing the relief setting on the laser grader valve. If the grader does not have a relief valve, the remote valve should have one.

If you are getting large hyd spikes from the grader hyd system, a hyd gage might help you monitor and troubleshoot the hyd system.

I called the guy who sold me the system today. He said it has to be some kind of back pressure that is causing the 'coil' to fail. He suggested I check with my Kubota dealer to see if there is another way to dump the return oil back into the tractor tank, besides the remote valve.

I was near a Kubota dealer, and stopped in to ask. A mechanic said that the only way he could think of to dump the oil back into the tank, would be to add a 'T' into the FEL return line.

The mechanic also suggested that I check the male quick connectors to see if they match my tractor's remote valve's female connectors. I discovered that the male connectors on the laser blade have a 'ball' type and the female part on the tractor is the 'flat tip' type. (Not sure if that's the correct term, but they are different)

Do you think the different types in the quick connections could cause a restriction? If that would be the problem, it would surely be an easy fix.

And, thanks again J_J for helping me with this issue.

 

[aczlan]

I called the guy who sold me the system today. He said it has to be some kind of back pressure that is causing the 'coil' to fail. He suggested I check with my Kubota dealer to see if there is another way to dump the return oil back into the tractor tank, besides the remote valve.
I was near a Kubota dealer, and stopped in to ask. A mechanic said that the only way he could think of to dump the oil back into the tank, would be to add a 'T' into the FEL return line.

The backpressure is probably caused by using the 3 point while the lever for the remote was engaged. Look at the back of your tractor, there is a fill port back there that you can put an adapter (such as seen at: http://www.tractorbynet.com/forums/attachments/115722-post-driver-hydraulic-hook-up.html#post1334294 ) onto and have a zero pressure return.

Aaron Z

 

[J_J]

On the ball an poppet type QD's, they should match.

I have never seen a flat face QD used with a b all or poppet type QD.

Again, match up the QD's as to manufacturer.

The fill cap is another to return the fluid directly from the laser grader.

A hyd gage would be helpful in sensing any hyd pressure.

Just add a tee in the pump hyd line and put it where you can see it.

 

[oldnslo]

The mechanic also suggested that I check the male quick connectors to see if they match my tractor's remote valve's female connectors. I discovered that the male connectors on the laser blade have a 'ball' type and the female part on the tractor is the 'flat tip' type. (Not sure if that's the correct term, but they are different)

Do you think the different types in the quick connections could cause a restriction? If that would be the problem, it would surely be an easy fix.

And, thanks again J_J for helping me with this issue.

Yes the different style QD's could cause excessive back pressure along with the increased flow potential from the Kubota. It looked like there may be a tank line gauge port on the valve body. If there is can you install a gauge in that port and see what the pressure does while the system is in operation.

 

[Complete Turf Care]

Here are pics of my male QD on the blade, and the female on the tractor. I'm going look at the valve to see if there is a place I could put a gauge.

 

[oldnslo]

On the picture in post #7 there appears to be plugs labeled TG & GP. Not sure if that is for tank gauge & gauge pressure or some other function.

Is the QD on tractor a flat face or poppet style? Almost looks like poppet style where there would be a cone shaped pice in the middle of the QD. Occasionally these will interchange with ball style but I have had them fail and block the flow which would then create back pressure on the tank line.

 

[Complete Turf Care]

On the picture in post #7 there appears to be plugs labeled TG & GP. Not sure if that is for tank gauge & gauge pressure or some other function.

Is the QD on tractor a flat face or poppet style? Almost looks like poppet style where there would be a cone shaped pice in the middle of the QD. Occasionally these will interchange with ball style but I have had them fail and block the flow which would then create back pressure on the tank line.

On the tractor, the QD is a poppet style, and on the blade, they are ball style. I'm gonna change those before I use it again.

Here are some more pics of the valve. I don't know if any of these ports would be for a gauge. And at the tip of my ink pen is where the oil comes out when the 'coil' fails.

 

[aczlan]

Look where the red box is in this picture. You will find an orangeish/yellowish cap that can be used as a pressure free tank return if you drill it out and tap it.


Aaron Z