Spool Valve Help Required

[certaindeath]

Hi All,

Looking for a little help with my hydraulics on my Mconnell Backhoe.

The unit has a 3 spool valve block for controlling bucket, and to arm rams. There was then a separate single valve for controlling the slewing rams. This slewing valve failed so I bought a spring return spool valve to replace it.

I hooked it up basically teeing into the flow and return connections for the 3 way valve. When I started up the hydraulics I had no response from any of the rams when moving the valve handles. I eventually removed the new valve connections and checked the 3 way valve was operational on its own and it is.

I then realised that both these valves are open centre so I was effectively pumping oil both ways into my new spool valve. My question is how can I get around this and get both valves working off the same flow and return lines.

Can I take the return from the 3 valve block and use it to feed the flow of the single valve? Or could I fit non return valves to both the return lines of both valves before the tee together so that the oil can't flow back up to the other valve?

Any help would be most appreciated. Trying to get the darn thing working so I can start digging up my drainage.

Thanks

Ian

 

[Tx Jim]

Welcome to TBN
Open center control valves must be attached in series but definitely not teed into hyd system.