hydraulic manifold ?

[wheelbuilder]

With only 3GPM and 1850 max PSI...depending on what the op has in mind for utilizing the new hydraulics for...I would consider an independent pump/system...

My hope is to power a pair of cylinders for a snow plow. After reading some more it looks like I could use Hoye's setup to feed a spool with power beyond to run the 3 point. The only thing to figure out past that would be returning the fluid neatly to the tractor, it doesn't seem like it would be neat and clean.

 

[/pine]

If there is a vent in the tank it could likely be modified to accept a return line...or modifying the tank fill cap...hydraulic returns are low pressure and can be Teed into any existing return to tank line...

 

[wheelbuilder]

I'll look at how I might use the filler cap for a return. I just am trying to think how fxrs55's setup would route the fluid. It seems like it should be simple enough to duplicate.

 

[Dave M7040]

I'll look at how I might use the filler cap for a return. I just am trying to think how fxrs55's setup would route the fluid. It seems like it should be simple enough to duplicate.

I think what you will discover is thatfxrs55's arrangement is actually a selector valve like an A or B switch.

Look at this one from prince.

Anytime you have a spool valve, it needs a return to reservoir line. It should also come with a relief valve internally which also uses the return line.

Dave M7040
Prince Manufacturing Corporation > Products > Hydraulic Valves > Selector > Model RD9

 

[wheelbuilder]

That makes sense. I would imagine then that manifold allows the return to be neat and clean while making a passage for high pressure from the selector valve to work the 3 point.

Would that setup retain enough pressure to keep either circuit in position while the other was active ?

 

[Dave M7040]

That makes sense. I would imagine then that manifold allows the return to be neat and clean while making a passage for high pressure from the selector valve to work the 3 point.

Would that setup retain enough pressure to keep either circuit in position while the other was active ?

The selector valve will lock fluid in the unused circuit. It will send pressure to two different control valves be they one or two spool, but you need two independent control valves. For more cost but less hardware, an electrical two circuit selector will allow you to use one control valve to operate two different circuits. Flip a switch and the circuit receiving power changes.

You find this arrangement on FEL's when the owner wants to add a grapple. The selector valve switches between controlling the bucket to controlling the grapple all by a button on a joystick.

Dave M7040

 

[wheelbuilder]

Thanks Dave, that's a big help !

 

[fxrs55]

My manifold is not any type of valve. It is just
high pressure in one side of manifold and out that end to
carry pressure to front blade valve assembly.
high pressure returns from control valves into
the other end of manifold and out the side
via a banjo bolt and the high pressure
then goes into the 3 point control valve.
Its just a pass through. I guess I will
have to take it off so I can get all of the
dimensions to make a drawing for anyone
who wants to have one of these made.

 

[wheelbuilder]

fxrs55 - I'm pretty green with hydraulics but from your pics and drawing that looks like an open spool plumbed neatly in before the 3 point. Pretty much what I was looking at with Hoye's adapters.

Dave - is that how you see it as well ?

If it works, I haven't found any spools that have more than a 500 psi rating on the tank side. I read Ampa's thread and he had issue with a cracked spool housing, I wonder if that's why.

 

[Dave M7040]

fxrs55 - I'm pretty green with hydraulics but from your pics and drawing that looks like an open spool plumbed neatly in before the 3 point. Pretty much what I was looking at with Hoye's adapters.

Dave - is that how you see it as well ?

If it works, I haven't found any spools that have more than a 500 psi rating on the tank side. I read Ampa's thread and he had issue with a cracked spool housing, I wonder if that's why.

Using the tank port as a supply for another circuit is a common mistake and usually results in the failure you describe of a crack in the valve body. Further, you eliminate a relief valve working properly as it needs a path to the tank to save you from destroying the pump. There is lots of junk hydraulic advice on the web.

This out port pressure restriction is common as you have found.

Years ago companies like Kubota made hydraulic blocks that could be added by their customers in order to acquire more circuits.

The big difference between the 3 pt hitch and the circuits you want to add is the 3 pt uses a single acting hydraulic cylinder, whereas, because you want to control double acting cylinders you need a control valve and not try to use the 3 pt control valve

Dave M7040