Remote valves and 3rd function

[dwalk19]

Hey guys sorry for millionth post on this subject, but im looking to add 2 rear remotes for sure and possibly a 3rd function, I have a couple/bunch of questions, I know I need to use PB from loader but is there a 3rd function valve manifold (D03 subplate/manifold) that also has PB capabilities, so i can leave that and feed my rear remote valve, and what is a decent 2 spool valve for a top and tilt setup, my tractor is a 2016 mahindra 2538, open center and I believe has a 7.6gpm system, thanks guys

 

[N2DFire]

Hopefully I'm not going to throw too much at you at one time but . . .

To begin with - here's the basic fluid flow loop on almost all SCUT/CUT's

Tank -> Pump -> Power Steering (if not fed from a separate pump/output) -> Loader Valve (Lift/Lower function then Dump/Curl function then out the Power Beyond Port) -> Rear Remotes (SCV's) if present -> 3 Point Lift -> back to the Tank

All of the actual valves (Loader, 3rd function, and rear SCV's) are "Open Center" which means that fluid flow will come in one side and, unless the valve is activated, flow out the other side and continue downstream.


You are correct on tapping the PB port from your loader valve but odds are this is already in use feeding your 3pt lift so you'll have to break into this leg of the circuit.

The D03 Subplate has 4 ports A & B work Ports, P (Pressure In), and T (Tank), however in the case of the sub-plate with an Open Center Valve, the T port doubles as the PB port

Probably about as clear as mud right now.


For the rear SCV's i'm not familiar with any of Mahindras factory options, but if you're going to mount/plumb an aftermarket block then keep this in mind - If you only do 2 and use those for T-n-T and then one day add some implement that needs hydraulics you'll have to disconnect something.

I would suggest at least a 3 spool if not 4 spool block - OR - I would get individual stackable valves that will allow you to add on later (don't forget to leave room for them where ever you end up mounting them).

I ended up adding the factory 2 Remote system to our Kioti (they are proprietary & the control handle slots were already there) with the thought that if/when the time came I needed to expand I would simply add diverters to the existing valves.

Also make sure you get at least 1 valve with "Float" - very handy feature.

I attached the write-up (including after thoughts & "Do Different's") from where I put a 3rd function on our Kioti. It won't be a direct How-To guide for you but it will cover some basic concepts and give you some things to think about.

 

[flingwing1969]

Thanks for that writeup N2DFire.

 

[dwalk19]

Yes thanks for the info, my tractor- mahindra 2538 currently has the loader and obviously 3 pt hitch, my plan is to break the PB connection on loader valve and run it into a D03 subplate(3rd function valve) out of the T port to rear remote valve (2 or 3 spool) with PB plug out, and then to a mahindra backhoe in and out and then back to feed the 3 point hitch, I know the spool valve will need a line to return back to the tank somewhere also, but does the jist of this sound correct, and as im typing this im just thinking of how much this is going to cost, but seems logical to do it all at once, then only have to get hoses made once,,,thanks for all the input
Dustin

 

[Dave M7040]

Yes thanks for the info, my tractor- mahindra 2538 currently has the loader and obviously 3 pt hitch, my plan is to break the PB connection on loader valve and run it into a D03 subplate(3rd function valve) out of the T port to rear remote valve (2 or 3 spool) with PB plug out, and then to a mahindra backhoe in and out and then back to feed the 3 point hitch, I know the spool valve will need a line to return back to the tank somewhere also, but does the jist of this sound correct, and as im typing this im just thinking of how much this is going to cost, but seems logical to do it all at once, then only have to get hoses made once,,,thanks for all the input
Dustin

DO NOT use tank port to feed another valve. The tank port will break. out of the T port to rear remote valve (2 or 3 spool) with PB plug out

Look at the low pressure rating of the typical tank port.
This is the pressure it will experience when you activate the valve being fed is used.

This is a typical consequence of a hydraulic mistake. Often involving very expensive and sometimes impossible to find part.

Perhaps I am not reading your plans correctly but your description sounds like a road to disaster.

There are web sites which show hydraulics interconnected as you propose but not all internet info is correct.

A possible solution for you to consider is to replace your existing FEL valve with one with perhaps 6 spools and power beyond.

That way you are not feeding one valve from the tank of the previous valve and the hydraulics will be much simplier when it comes to hoses etc.

Dave M7040

 

[N2DFire]

DO NOT use tank port to feed another valve. The tank port will break.

On a CLOSED CENTER system you are quite correct, however this is an OPEN CENTER system.

On Open Center when the valve is not in operation fluid flows in the P port, thru the valve body, and out the T port.
When Operating Function A; P goes to A to provide system pressure to the working side of the cylinder and B goes to T to dump the low pressure fluid from the non-working side.
When operating function B the opposite cross connection occurs.

Therefore on a D03 subplate there is NO OTHER port for fluid to exit other than the T port. You have A & B work ports, a P port for Pressure In and a T port for Pressure Out.

Also remember that the subplate is just a hunk of aluminum with 4 passageways milled into it. The aluminum does not suddenly get weaker on one port simply because you labeled it with a T - all 4 ports will withstand all the same pressure. Only the D03 pattern on the face & the indexing pin determine which passageway performs each function.

1 Station DO3 Subplate Open Center | Subplates | Hydraulic Adapters & Fittings | Hydraulics | www.surpluscenter.com

Yes thanks for the info, my tractor- mahindra 2538 currently has the loader and obviously 3 pt hitch, my plan is to break the PB connection on loader valve and run it into a D03 subplate(3rd function valve) out of the T port to rear remote valve (2 or 3 spool) with PB plug out, and then to a mahindra backhoe in and out and then back to feed the 3 point hitch, I know the spool valve will need a line to return back to the tank somewhere also, but does the jist of this sound correct, and as im typing this im just thinking of how much this is going to cost, but seems logical to do it all at once, then only have to get hoses made once,,,thanks for all the input
Dustin

Dustin,
If your rear remote spools are also Open Center then you shouldn't need a separate return to tank line, they should work just like the 3rd function valve above.

Everything else sounds right to me except for the backhoe - and that is because I have no knowledge or experience with those so I'm not sure how the valving works.

I would assume they are all still Open Center, in which case what you propose there is correct as well. It's a fairly low risk assumption, but an assumption on my part nonetheless so please verify that with someone more knowledgeable (your dealer or maybe ask in the Mahindra specific form as well).

 

[dwalk19]

Yes it is an open center system, so from my understanding the D03 subplate will be able to handle the pressure through the subplate ok to feed the next set of valves, I tried searching for a subplate with PB, but everything I read said doesn't need to have it

 

[LD1]

Couple days late to the thread, and cannot really offer the OP any advice on selection....because there are many many ways and many many choices of components.

But regarding PB and tank.....

In a typical cast iron manual valve.....it is absolutely true that you do NOT want to use the tank port for PB purposes.

However on a typical electric valve with a subplate, the tank ports usually ARE rated for system pressure and no need (or even a provision) for PB.