I've noticed the MC gets very hot after braking for a while. It is too hot to hold your palm against the metal part of it for more than 2 seconds.

Thr brakes work fine, and aren't dragging. The rotors are not getting very hot.


Is it normal for the master cyl to get this hot ?

 

You may be generating some heat from braking, and that heat may be transferring through the fluid back to the MC, but it shouldn't be that hot after conducting through the tubing back to the MC. It's more likely that the MC is getting heat radiated to it from the LH exhaust manifold.