extra hydraulic valve

[gerard]

I'm in the market for a backblade and saw one advertised that has a 6 way hydraulic adjustment. I assume I need to have valving added to my tractor to control it and was wondering how cost intensive that would be. I have a FEL now with float if that comes into play.

 

[W5FL]

There are lots of ways to do this. The factory way is about $750 per pair of valves which includes a control lever for them. Many tractors are NOT equipped to use more than one or two valves until you get into pretty large tractors. I have seen a nice hydraulic switch that had 3 switches on it. The original SCV lever was used to control all three of the box blade functions and the switch only selected the one to be controlled. I would like to have the additional valves at times, but stubbornly make out with the one that came on my tractor and will probably add another one as soon as I can't do what I need to do. There was a recent thread about adding a valve at very low cost, that you should read. The pieces are not cheap and need to hold up to the nearly 3000 psi operating pressure and be very reliable.

 

[TomG]

I think a fairly cheap approach is to add a section to the existing loader valves, which would give you and additional hydraulic pair to use for 3ph implements. Then, order a three section valve (6 way blade is 3 cylinders I guess), mount it someplace convenient and run it from the section added to the loader valves.

That's the way I run my backhoe. The hoe has its own plumbing, and all it needs is a pressure line and a return line. I just connect the hoe to the rear pair and hold the rear hydraulics valve open with a bungee cord. Of course, I do have to keep careful track of which rear hose gets pressure when the valve is held forward. Connecting hydraulic lines backward damages things quickly.

As I understand: with an open centre system, flow goes to the input section of the spooling valves. If no valve is open, the flow goes out the output section and returns to the reservoir. If the rear hydraulics valve is held open, flow goes out the pressure side of the valve, into the hoe input, back out the hoe output (unless one of the hoe valves is open), through the return line to the rear hydraulics valve, on the output section and finally back to the reservoir.

I added this explanation mostly as a way of testing my own understanding. The explanation, or a response to it, might be useful for somebody like me who is trying to get the mind around hydraulics