I checked your posts as well and i will flush the system again tomorrow and put some fresh DOT5.1 fluid. It has a higher boiling point than the DOT4.
It's so frustrating cause i have a friend with a 998 and can you imagine he changed the fluid only once in 10000 km... i envy these guys.
Did you find the use of the adjustable pin that actions the piston of the pump at the lever???