can a spool valve be to big?

[footer200]

I have a 2001 John Deere 4300 and have be thinking of adding 3 sets of remotes out back. I just found out I can pick up this valve for next to nothing [80 bucks]. MD30 3-Spool Directional Control Valve | Princess Auto My tractor flows 13 gpm but this valve can handle 25 gpm and the ports are large. I can step down the ports but just wonder what the thought was on this valve. I know there is no float or detent.

 

[Arc weld]

I think you should be OK.

 

[J_J]

Sometimes you have to use what you have, but

You will notice that when the lever is at half way point, you are passing all the fluid the pump can flow. More lever will not do much.

You will not have the finesse as you would if the valve matched the pump flow in GPM's.

 

[Leejohn]

When you chock down the out port, say maybe to 3/8 it should help and work, but not as good as one the right size.

 

[TomSeller]

I put a 25 GPM 3-spool on my 14 GPM pump because I didn't want a significant pressure drop (ports through FEL, this spool, then another spool, then the backhoe assembly). It is fine, no objections. Still plenty of control in the first portion of travel. Like JJ says you get all your action at the beginning of the lever action. But it really isn't noticeable to me now that I am used to it. I can still feather it out. I would never put a spool that is rated at less than the pump, you will get a pressure drop.

 

[footer200]

Ok great thats what I needed to know. I think I will wait and get the stackable valves and get the float and detent where needed.Thanks for the quick replies.

 

[dfkrug]

I have a 2001 John Deere 4300 and have be thinking of adding 3 sets of remotes out
back.

Although your tractor pumps only 8.3 GPM (not 13) thru the implement pump, I have no problem
using 25GPM-rated AUX valves. Indeed, I prefer them and have used 25 GPM AUX valves on
CUTs putting out only 7 GPM (JD 955 and Kubota L2550). For this application, the valve is
usually installed between the FEL valve and the 3-pt valve, so it must have power-beyond.

I like the reduced resistance to PB flow, versus say, 10 GPM valves, and therefore cooler oil.

I will probably change my Kioti's OEM AUX valve to a 3rd party 25 GPM unit for this reason.
The Kioti is also 8.3 GPM.

 

[J_J]

Ok great thats what I needed to know. I think I will wait and get the stackable valves and get the float and detent where needed.Thanks for the quick replies.

The stackable valve is a good plan as you can tailor make the setup with lots of options.

It makes no sense to use larger valves, as stated above. They cost more, and the restrictions on a matched up GPM flow is minimal.

On larger valves, you will probably have to reduce the port size to match up the hose size on the tractor.

So essentially, the smallest hole size on a valve, hose , hyd block, whatever, will limit the flow somewhat. You don't gain much by going bigger.