ok your master is a cylinder with seals in it. when bled your brake stroke will be say only 1/3 of pedal travel. so only 1/3 of cylinder is being used now if the fluid in the system is contaminated with moisture the other 2/3 of the cylinder could be corroded.
So when u bleed system manually you pedal to floor using all cylinder passing seals into a possible dodgy area where the seal could get damaged.
Hadthis many years ago on a metro
better?
Last edited by costina; Aug 25, 2012 at 09:02 PM.