How do i size a Aux loader valve? Putting it in series.

electrycmonk · Feb 3, 2020

now this is wisdom I'm glad i read..... thanks for helping him....and me too from lurker mode. ;>)

Tx Jim · Feb 3, 2020

aczlan said:
That would be plain Open Center, not Open Center with Power Beyond.
The advantage of Power Beyond is that in an Open Center system, if the 3 point it trying to raise, the spool valve has to create enough pressure on the output side to raise the 3 point AND do whatever work the spool valve needs to do.
A Open Center system with Power Beyond lets the "spent" fluid from each valve return directly to the tank and does not force it to do whatever other work needs to be done further down the loop.

Aaron Z

My original statement was not all open center hyd systems require PBY.

I know the difference between plain OC valve & OC valve with PBY. After serving as a dealer service manager for 13 yrs I have fairly good knowledge of the different types of hyd systems.

Burns331 · Feb 3, 2020

i dont think my Yanmar EX3200 has a Power Beyond Plug on the loader valve. This would be the best design for sure. Otherwise i dont know how else to get this done. Basically interrupt the feed line to the loader valve, and pass everything in series prior to it. I agree i would prefer to have the loader be first in line.

Also what i meant for a loop was run my full pressure line to the back of the tractor, and have a quick connect on it. And then have a line going from the back of the tractor back to the AUX valve or loader valve. Then when im not using a 3pt attachment hat has hydraulic needs, just put a loop between the IN/OUT lines on the back of the tractor to pass hydraulic fluid forward. When using a wood splitter, or backhoe, you remove the loop, and tie your equipment to the IN/OUT hydraulic fittings.

ptsg · Feb 3, 2020

Tx Jim said:
ptsg
Please explain how the hyd systems on older tractors built in the late 40-60's had external control valves added to their existing hyd systems without catastrophic valve failures before PBY came into existent? . I'm referring to hyd systems on tractors such as Farmall H &M & JD 420 that I witnessed the hyd systems operating fine with added remote control valve without the aid of PBY.
Thanks,Jim

Tx Jim said:
My original statement was not all open center hyd systems require PBY.

I know the difference between plain OC valve & OC valve with PBY. After serving as a dealer service manager for 13 yrs I have fairly good knowledge of the different types of hyd systems.

Your statement left the impression that the requirement for PB is related to GPM, which I then said it's not. It has to do with pressure and how the valves are made. There is the risk of cracking valve bodies if the tank port is pressurized.

That being said, my homemade backhoe has the valve for the drive motor feeding the backhoe valve using the tank port, but I do have a external main relief valve for the system. It has been like that for years and so for so good.

And those old tractors would hardly put out any significant GPM or pressure.

Tractor Seabee · Feb 3, 2020

Burns331 said:
i dont think my Yanmar EX3200 has a Power Beyond Plug on the loader valve. This would be the best design for sure. Otherwise i dont know how else to get this done. Basically interrupt the feed line to the loader valve, and pass everything in series prior to it. I agree i would prefer to have the loader be first in line.

Also what i meant for a loop was run my full pressure line to the back of the tractor, and have a quick connect on it. And then have a line going from the back of the tractor back to the AUX valve or loader valve. Then when im not using a 3pt attachment hat has hydraulic needs, just put a loop between the IN/OUT lines on the back of the tractor to pass hydraulic fluid forward. When using a wood splitter, or backhoe, you remove the loop, and tie your equipment to the IN/OUT hydraulic fittings.

Can you get a diagram of your tractor's system? That will clue you in. If you cannot determine the PB port on your FEL valve or get a PB sleeve; just insert your new valve W/PB ahead of the FEL valve and pipe to the inlet on your FEL valve. Order the new valve with the PB sleeve, you will get an instruction sheet w/it. Don't forget to connect the new valve T port into a new tee in the T (tank) line.

Remember it is hard for us to visualize your system w/o pictures and/or diagrams. One line diagrams tell the story best.

Ron

BukitCase · Feb 3, 2020

"Order the new valve with the PB sleeve"

AND a RELIEF VALVE that dumps back to tank. If necessary, I can probably post a pic or two of the PIECES OF MY OLD HYDRAULIC PUMP -

The pump literally EXPLODED when I plumbed a Samurai cutter in AHEAD of the loader valve (with its built-in relief valve) on my 580B - happened when the cutter met a hardened laurel branch that stalled the cutter. Same thing can easily happen to any OTHER hydraulic add-in, like end of travel on a cylinder while still holding the lever. Remember, the VERY FIRST thing your pump should see is a relief valve.

That was a $450 MISTAKE I wouldn't wish on anybody... Steve

Burns331 · Feb 3, 2020

Here is the factory install setup, but i cant find the kit anymore, i think its all been discontinued. Hence i want to make my own.

Burns331 · Mar 16, 2020

So im just going to skip putting PYB on. Im just going to go inline from the pump out to the new aux valve and then to the rock valve like the OEM. Which brings me back to what sizing. I think my OEM pump on my tractor is 5.6 GPM. So do i just get a dual stick that flows that much?