So lately I've noticed decreased performance from my hydroboost pump, mostly in the brakes. It seems like I have to push the pedal harder to achieve the same braking power than i did 6 months ago. Also the past couple times I've done one of my high speed late night backroad runs after a series of hard cornering and braking the pump begins to whine as if it is out of fluid and I feel the vibration in the brake pedal. I've done some research and it seems that flushing the system and replacing the fluid with synthetic helps some but I am also curious are there any pump upgrades such as putting a smaller pulley on the pump or a whole new performance pump of some sort? Also does anyone know what actually causes the whining condition of the pump? Is it overheating of the fluid? If so I was thinking of installing a trans cooler in the hydroboost system? Any input is appreciated.