Replace Loader Controls

tcarter1 · Aug 24, 2010

I have a Kubota M4700 with Bush Hog 2345 QT fel. The cyclinders and hoses all appear to be in good shape. The loader lifts fine, Problem is the controls are really sloppy, it doesn't curl and dump smotthly, and won't float.

Would replacing the controls be the way to go? Suggestions on what to use?

J_J · Aug 24, 2010

Check these out as a replacement.

First spool has regen, and second spool has float.

https://www.surpluscenter.com/item.asp?item=9-7401&catname=hydraulic

https://www.surpluscenter.com/item.asp?item=9-4782&catname=hydraulic

Also has PB capability.

tcarter1 · Aug 27, 2010

My pump is rated 11 gpm. Any danger of a 10 gpm being too small? I had heard to not use a valve rated less than your pumps max flow, but will 1 gpm really make a difference?

J_J · Aug 27, 2010

Probably not, because, if the tractor rpm is not at max, you are not pushing 11 GPM. Most times the fluid is flowing through the valve, and if the ports are 1/2 or 3/4 in, should be able to handle the volume.

tcarter1 · Aug 27, 2010

Better going with the smaller valve with regen as opposed to larger one without if I want to speed up curling/dumping the bucket? Looks like both of the ones you recommend float and have double action. Dual action means I can lower/dump lift/curl silmutaneously, correct? Looks like my existing fittings will match the 3/4" ports on the larger pump.

Egon · Aug 27, 2010

Take a look at the mechanical linkages and see if they are worn.

They do wear out as I found on my little B7100. Three sets in 3000 hours.

AKKAMAAN · Aug 29, 2010

tcarter1 said:
My pump is rated 11 gpm. Any danger of a 10 gpm being too small? I had heard to not use a valve rated less than your pumps max flow, but will 1 gpm really make a difference?

You have an open center system, in which entire pump flow is passing through the valve all the time engine is running.....It is definitely to ask for heating problems to go for the lower rated option....a lower rated valve will also reduce the hydraulic power to the cylinder/motor (pressure drop)...
Only if you run engine below the rated pump rpm's (example 11 GPM at 1500 rpm), you can get by with a smaller valve

(note: on a closed center system, the heat problem would only occur while directing oil to work port/cylinder, so in that case heat problem would be a matter of how frequent valve is used...)