So I ran the controls into the cab, removed the old plow controls, replaced a pressure line, added fluid and the damn thing wouldn't lower. Lifted fine, but no drop. Even with a giant bar chained to it. Pulled all the solenoids, cleaned and operated on the bench and reinstalled.
The old crusty line connected to a filthy hydro block.
My 5 foot snipe chained to the boom.
The hydro block, after I cleaned all the valves and coils.
The pump with a very clean hydro block.
Still nothing, after cleaning everything, but I could lever the boom down with the bar a few inches. On this system the boom and wings power out, and gravity or spring pressure pulls the rams back. After levering the boom down if I released the wings the boom would lift a little.
The I realized the damn pressure and return lines were connected to the pump backwards.
Connected backwards the pump would pressurize all the rams, and return would dead head against the pump..
I guess with a bad line it may have somewhat worked. The bad line would have released pressure enough for the boom and wing rams to creep down.
The new line connected the right way. Mmm, china.
This came off an old farm truck, and was barely used the last 5 years, so who knows what happened. I need to stop assuming things are assembled right.