Combines 860 loss of power steering

Hi Deerebines Check the pump. It has two circuits one for the powersteering and one for the header lift. Ten years ago I lost my powersteering but everything else worked fine. I was ready to do everthing you described but didn't have the time so I called the dealer and he hooked up the hydroanalizer to the combine and discovered the low flow high pressure circuit on the pump was bad . You likely need a new pump. Keep the old one for some application that just requires a single circuit down the road. Good luck.

The hydraulic pump contains a relief and flow divider valve. The flow divider is to insure a prority flow of 3.5 gpm to the steering circuit before allowing oil flow to the machine hydraulic circuits. It is obvious that you have no flow to the steering circuit, and I would therefore check the flow divider inside the pump. It has a spring-loaded spool inside a matching sleeve, and the spool is cross-drilled and contains a fixed orifice; this may be plucked up! Check that first before you consider another pump. The pump is NOT complicated; maybe you could have it reasonably overhauled. Good luck.....B.

does yours have a filter on the outlet of the priority head, if so it may be blocked ,i think they are extremely fine

as B said it has to do with the priority vavle in pump, on mine a small screw came loose that holds the spring that centers the spool any way thats were to look