If you are not loosing fluid and there is no evidence of brake drag. I would change the fluid in the drive axle and see how the brakes work. The wet brake system does not take a lot of pedal pressure to activate compared to the dry brake system. I have had customers add DOT3 fluid to the brake system. The brakes began to drag almost right away. The DOT3 fluid destroys the pad material and swells up the piston seals. didn't take long and there was no brake pedal and you could not get the system to bleed. Make sure you use the proper fluid in the axle. The new spec is J21A- John Deere or equivalent.