KUBOTA 3RD. Remote Hydraulic Controll - Installing direction solenoid valve

[AUSL4600]

What does the By port connect to today? Lee john is correct if the is an open center system then the By port must be connected to something to operate correctly.

My guess is it is connected to the Power beyond at the front end loader. Difficult to say for sure as I don't have the hydraulic diagrams.

Just so I am clear in what I am trying to do...I want to remove the end cover assembly (in red circle) and replace it with a custom aluminium manifold and bolt a solenoid valve on it.

It wouldn't be easy to directly connect to the By port on its own as you can see in the attached image.



Cheers,
John

 

[Leejohn]

I'm going to do some guessing and if'n. If you look there are 3 holes with o rings in each spool until you get to the end cap. Now "if" that end cap has a plug in it as it looks like it might and "if" there is threads between the last 2 holes so you could screw in a pipe plug to block the loop. Then send the oil out the hole that was plugged to the P port on the electric valve and you need a way to tape back in the end cap at the 3rd o ring hole. It should be easy to line it up if drilled from the inside out, the tape it. You do have to make sure the center hole is the feed from the pump. Also you might want to check the price of the cap, just incase it doesn't work or you mess it up. Don't do anything until you look it over real good and Roy might pop back in see what he thinks, he"s a lot sharper then me when it comes to this.

 

[Leejohn]

One more thing. When unscrew the bolts that holds it all together you have 9 o rings to get back right. I would pull the seat and pan under it, and that seat is heavy.

I just went back and looked the valve drawing and it shows the small o ring is the pump feed, but it still could be done just from the other end of the end cap.

 

[AUSL4600]

One more thing. When unscrew the bolts that holds it all together you have 9 o rings to get back right. I would pull the seat and pan under it, and that seat is heavy.

I just went back and looked the valve drawing and it shows the small o ring is the pump feed, but it still could be done just from the other end of the end cap.

I have a small CNC mill so I plan on making a completely new end cap with ports for the electric valve.

So is this what you are suggesting. Send the P flow through P on electric valve... remove flow through By? (see picture)

What solenoid valve should be used? Closed, open or tandem?

Thanks,
John

 

[oldnslo]

John,
Do you a complete hydraulic system schematic for your L4600? If yes could you post a copy of that please.

Like LeeJohn I am doing some serious guessing here.

In looking at how this valve is mounted I suspect the end cap you want to remove just directs the oil from the "P" channel to the "By" channel in the valve casting. The "By" port of this valve stack connects to the housing in the picture Fig H301xx. I suspect this then feeds the 3 point hitch. To replace that end cover would require a tandem center valve with the tank line capable of handling full system pressure. Connection to the tandem center valve would be P to P & tank to By.

My guess on the oil flow path of your tractor is: Pump to front loader valve, front loader valve to rear remote valve, rear remote to 3 point hitch, 3 point to tank.

To test flow path as your tractor is today. Engine can be at an idle for these tests.

Raise your loader high enough to curl and dump the bucket.

While curling or dumping with the valve shifted fully, will the rear remote functions operate?

With rear remote valve shifted fully does the 3 point hitch lift?

As an option does Kubota offer a solenoid operated option for your existing valve?

 

[Leejohn]

I looked to see if I had a parts manual and I didn't. It just seems like there should be a better place to tap into the system.

 

[AUSL4600]

Do you a complete hydraulic system schematic for your L4600? If yes could you post a copy of that please.

Unfortunately I don't.

In looking at how this valve is mounted I suspect the end cap you want to remove just directs the oil from the "P" channel to the "By" channel in the valve casting. The "By" port of this valve stack connects to the housing in the picture Fig H301xx. I suspect this then feeds the 3 point hitch. To replace that end cover would require a tandem center valve with the tank line capable of handling full system pressure. Connection to the tandem center valve would be P to P & tank to By.

Yes this was exactly what I was thinking was the case. The tandem center valve option was one I flagged previously. My only concern/question before - using the tandem center valve with tank (T) hooked to the By what would happen if you actuated any manual valve whilst the electric solenoid valve was at idle or in operation. Would the flow through the solenoid valve simply just stop or reduce?

My guess on the oil flow path of your tractor is: Pump to front loader valve, front loader valve to rear remote valve, rear remote to 3 point hitch, 3 point to tank.

Yes I believe this to be the case also.

To test flow path as your tractor is today. Engine can be at an idle for these tests.

Raise your loader high enough to curl and dump the bucket.

While curling or dumping with the valve shifted fully, will the rear remote functions operate?

With rear remote valve shifted fully does the 3 point hitch lift?

I have already tested the loader case and it showed that during lifting/curling of the bucket there was a reduction in speed (flow) when the 3rd aux valve was actuated. The 3rd aux did work as well at what appeared to be a reduced rate too.

I need to test the 3 point case today.

As an option does Kubota offer a solenoid operated option for your existing valve?

I don't believe so, I'm just trying to see if I can do it as a small project. Trying to make something that looks OEM.

Leejohn:
I looked to see if I had a parts manual and I didn't. It just seems like there should be a better place to tap into the system.

Yeah there probably is, as mentioned above just trying to make something OEM like. I am wanting to avoid running hoses everywhere.


Thanks to you both for your help.

 

[oldnslo]

If the solenoid valve is in the spring loaded center position or energized the manual valves will operate like normal.

If the solenoid valve is energized, the return flow from that feeds "By" passage If a manual valve is shifted the solenoid function will stop since shifting the manual valve blocks the "By" passage

 

[AUSL4600]

If the solenoid valve is in the spring loaded center position or energized the manual valves will operate like normal.

If the solenoid valve is energized, the return flow from that feeds "By" passage If a manual valve is shifted the solenoid function will stop since shifting the manual valve blocks the "By" passage

Yeah this makes sense.

I tested the 3 point hitch whilst the 3rd aux were in operation. As suspected the 3 point does not work with any of the 3rd aux valves actuated.

I will design and fabricate the manifold to hook to a tandem solenoid valve, with the P hooked to P and Tank hooked to By.

Will update once complete.

Thanks for your help!

John