Combines N6 Hydro Surging

My 85 N-6 also surges in full forward position. Can't say I have ever tried full reverse. Otherwise it seems fine and has never had any service done on it. I am just guessing but maybe charge part of hydraulic pump is not doing its job in supplying enough oil at full output of hydrostat.

local service manager suggested charge pump may be the problem but first change the filters. Did that and no improvement. But is variable in it's surge which leads me to believe its a sticky valve somewhere in the system as one would think a weak pump would be constantly weak. Gotta keep going for now.

likely have to get flow rater hooked into line charging hydro. Sould get all of the 5.5 gal threw flow divider that is fed to steering and then to hydro charge. If pressure falls approx 100 PSI below hydro charge setting the oil should come from hydro charge makeup valve in valve stack which will try keep hydro charge pressure by feeding it oil required. It will need some pressure testing to help determine if in hydro or oil feed to it. Good luck