I have a 930g cat loader and the brake pressure warning light/alarm keeps going off when the pedal is pressed , we have tested the brake pressure at 750 psi and have also checked to make sure accumulator Is working it is putting out 750 at first hit of the pedal and approx. 100 psi every hit there after I have had the brake valve apart and resealed couldn't find anything wrong with it, also replaced the sensor on the brake valve and the sensor on the brake/fan hyd pump that drives off of the engine . cat is telling me the brake pressure is ok at what I tested . what am I missing that would set the light /alarm off ? please help thanks!