You don't have to touch it,if the level is correct now just leave it,unless you have a leak(your brakes fail or become spongy)you don't need to top up,the fluid will drop slightly as the brake pads wear down, when the pads are renewed it will come up again,don't worry about it they either work or don't if there is a problem the MOT test should pick it up.
a, February 2010
