ISO general advice on adding remotes to '97 Kubota 4850

[Brambleberry]

I've got a '97 Kubota 4850, with EverClutch hydraulic shuttle shift. I love this tractor, but it has zero hydraulic remotes and no second function on the loader. I'd like to add both, but don't know enough about the details to know where to start. I want two sets of remotes to be able to run a ditch-bank style flail mower. I don't expect to need 3 sets for anything, but you never know.

Friends have told me that kubotas are picky about taking random hydraulic components, but I wonder if this is actually true. I am not very picky about making do with used or non OEM parts and I see them all the time on FB marketplace and ebay.

Is there any good links to basics of DIY hydraulic features, or posts on this forum that I could dig into? I have a basic idea of how the hydraulic system works, but just don't know enough to start buying parts and building the system. I have replaced hoses, and even tapped into the bottom of my old Zetor 5211 to plumb a set of remotes, but the company I bought the parts from walked me through that.

TIA,

Darren

 

[Harry in Ky]

I'm not familiar with that model, but if it has the Kubota LA950 loader and the associated plumbing, then you should have the hard part done. It would be a simple matter to tie into the existing hydraulics and add whatever valves, couplers, etc you think you might need. There are dozens of valves out there with the characteristics you need. Eleven GPM, open center, power beyond capable. Simple enough project you don't need to take a hydraulics class to accomplish. That sort of thing is done all the time.

Just my personal opinion here, but I would suggest you go strictly manual valves, nothing electrical. Your choice of course. Some here think solenoid valves are all the rage.

 

[Brambleberry]

Yes, it's got the LA 950 loader installed. I lean towards mechanical components whenever possible, so that advice lands on listening ears . It's actually why I drove from s IN to eastern VA to buy this tractor, I wanted an older style diesel pre-common-rail. And the L50 series are known to be excellent.

So basically I can just tee off just before the loader valves? Then just decide where and how to mount lines, valves, and couplers?

 

[Harry in Ky]

Check your PM inbox.

 

[ericm979]

Your tractor has an open center system like most CUTs. Each valve, when in neutral position, flows to the next valve in the chain. Right now your loader would be first in the chain and the 3pt second. You can't tee off the pressure line ahead of the loader, because then flow will take the path of least resistance so you'd get no work done unless you operated the loader at the same time as the remotes.

The 3pt is always last in the chain because its output dumps directly into the gear box casing, which is also the hydraulic tank.

So what you want is to add your new valves between the loader valve and the 3pt. The loader's power beyond port, which is now connected to the 3pt, will go into the input of your 3rd function valve. It's tank port then feeds the rear remote's input port.

Typical 3rd function solenoid valves have two work ports, an input and a tank port. Typical remotes will need three port in addition to the work ports- input, tank and power beyond. You can get spool valves without the PB port but their tank ports usually can't handle the pressure that they would get when valves farther down the chain are operated.

 

[nyone]

Post a picture of your loader valve.

 

[rScotty]

Your tractor has an open center system like most CUTs. Each valve, when in neutral position, flows to the next valve in the chain. Right now your loader would be first in the chain and the 3pt second. You can't tee off the pressure line ahead of the loader, because then flow will take the path of least resistance so you'd get no work done unless you operated the loader at the same time as the remotes.

The 3pt is always last in the chain because its output dumps directly into the gear box casing, which is also the hydraulic tank.

So what you want is to add your new valves between the loader valve and the 3pt. The loader's power beyond port, which is now connected to the 3pt, will go into the input of your 3rd function valve. It's tank port then feeds the rear remote's input port.

Typical 3rd function solenoid valves have two work ports, an input and a tank port. Typical remotes will need three port in addition to the work ports- input, tank and power beyond. You can get spool valves without the PB port but their tank ports usually can't handle the pressure that they would get when valves farther down the chain are operated.

I'd agree with all that, except that in the third paragraph of your message above where you wrote, "It's tank port then feeds the remote's input port."

I think that should instead read, "Its POWER BEYOND port then feeds the rear remote's input port.

Another way to do that would be to replace the existing two spool loader control valve with a three spool valve with power beyond. That would be simpler and the extra spool could be used for the forward remote. The power beyond then leads to another of the same valves used for the rear remotes, and that power beyond goes to the 3pt hitch. Prince makes that valve in the right GPM size.

There are lots of ways to get that done.

From the SurplusCenter.com:

3 Spool Prince SV Sectional Control Valve Open Center w/Power Beyond​

ITEM NUMBER: 9SV-3-Y

rScotty

 

[ericm979]

I'd agree with all that, except that in the third paragraph of your message above where you wrote, "It's tank port then feeds the remote's input port."

I think that should instead read, "Its POWER BEYOND port then feeds the rear remote's input port.

On valves with a tank and a power beyond port the PB port feeds downstream valves. BUT on a valve with just one output, like all the 3rd function solenoid valves I have seen, the single output is called the tank port even though it feeds the downstream valves like the PB port on a normal valve. It's confusing but that's the naming convention. I was referring to a solenoid valve in that paragraph.

The difference, besides the number of ports, is the pressure that the tank port can withstand. On valves with a PB, the tank port is rated to 600 psi or so. But the system pressure can usually reach 2100-2300 psi.

Just to make it more confusing, there are some manual spool valves without a PB port. Sometimes the tank valve is good for high pressures, sometimes its not. You have to dive into the spec sheet to see.

 

[rScotty]

On valves with a tank and a power beyond port the PB port feeds downstream valves. BUT on a valve with just one output, like all the 3rd function solenoid valves I have seen, the single output is called the tank port even though it feeds the downstream valves like the PB port on a normal valve. It's confusing but that's the naming convention. I was referring to a solenoid valve in that paragraph.

The difference, besides the number of ports, is the pressure that the tank port can withstand. On valves with a PB, the tank port is rated to 600 psi or so. But the system pressure can usually reach 2100-2300 psi.

Just to make it more confusing, there are some manual spool valves without a PB port. Sometimes the tank valve is good for high pressures, sometimes its not. You have to dive into the spec sheet to see.

Here is a popular Prince single spool valve with power beyond. Very reasonably priced. That or the conversion to a 3 spool loader control alve would be good choices. I'd base a decision on the system flow and consider how much flow is diverted for steering.

You are right that return flow ports can withstand different pressure ratings, but I still wouldn't use a tank return port as a pressure port. In my opinion, the system has finer control if all return lines have very little pressure.

Prince Mfg MB11B5C1​

COMPACT 1 SPOOL DOUBLE ACTING DIRECTIONAL CONTROL VALVE
Brand new WOLVERINE by PRINCE MB series directional control valve for operating double acting cylinders. Ideal for small tractor and other low flow applications requiring a compact control valve. Features include monoblock construction, load check, built-in adjustable pressure relief valve, spring centering spool action, open center with enclosed plug to convert to power beyond or closed center, side or top inlet/outlet ports and vertical or horizontal handle mounting.

1 Spool 8 GPM DA Valve Wolverine by Prince Mfg MB11B5C1 | Directional Control Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com

1 Spool 8 GPM DA Valve Wolverine by Prince Mfg MB11B5C1, Directional Control Valves, 1 SPOOL 8 GPM PRINCE MB11B5C1 DA VALVE, COMPACT 1 SPOOL DOUBLEWolverine by Prince,MB11B5C1 ,

www.surpluscenter.com

 

[rScotty]

Yes, it's got the LA 950 loader installed. I lean towards mechanical components whenever possible, so that advice lands on listening ears . It's actually why I drove from s IN to eastern VA to buy this tractor, I wanted an older style diesel pre-common-rail. And the L50 series are known to be excellent.

So basically I can just tee off just before the loader valves? Then just decide where and how to mount lines, valves, and couplers?

Just checking that you understand that you cannot do a simple Tee anywhere. The flow needs to have all of the control valves in series.

The way the open hydraulic system works is that the Power Beyond (PB) port from the first control valve feeds the input to the second valve and so on. You can daisy chain them together until fluid friction makes it impractical.
The work ports on each valve are essentially the metered "Tees" that activate each cylinder.

Every control valve in the series has it's own return line. All the returns can be Y'd together - but the return line has to become larger with each new line that joins it. The return line dumps into the sump at atmospheric pressure.

What we don't know yet is if your first control valve - the one for the FEL - has a power beyond (PB) port. If it does, it will need the insert installed. Or if no PB port then replace with a directional control valve that does have a PB port and proper insert.