[Ray]

I've had me 998 boil up it's rear fluid a time or two, I do tend to use the rear brake quite a bit.

A fluid change could well cure it, if the fluid is old it boils more easily as it's hydroscopic and the increased water content lowers its boiling point.

Brake fluids have a dry and wet boiling point. The wet is usually a lot lower, in some cases an couple of hundred of degrees lower.

Ray.