Loader M4900 has hard steering and slow hydraulics when hot

[readbranch]

I have a 2007 Kubota M4900 with about 700 hours on it. (bought used) We changed hydraulic fluid and filters (with Kubota brand oil and elements) when we first experienced stiff steering and slow hydraulic response (after about 3 hours of running). We left the tractor in the field overnight and then it ran normally as if nothing had been a problem the night before. Yesterday (95 degree day) we were discing a field for a little over 3 hours when it began to show the same symptoms - slow front and rear hydraulics and stiff steering. It seems this may be related to heat? Is it possible the oil thins out after running a while (especially working hard and/or in extremely hot conditions) and leaks past the pistons of the pump? Has anyone else had such a problem and solved it? Thanks. Read

 

[KennyV]

Exactly what hydraulic oil is in it...

The next time it happens check the Hydraulic oil temperature... KennyV