Clunk from brake pedal while depressing brake in cold weather: brakes drained, filled, and bled at no cost.
Rear pads were worn out. They actually fell apart and locked up left rear brake
Knocking sound was coming back slowly, even with new disks and pads. Dismantled, cleaned and relubed with synthetics. Specialy the caliper pins which were quite dry. Pins out of calipers and boots throughout clean job. Works good.
Squeaking break pedal. Replaced fluid in master cylinder. Not fixed 100% of the time but better.
Anti-lock brakes, Traction control and Parking brake warning lamps came on simultaneously. Replaced brake control module.
The brake fluid in the master cylinder started to break down about 3 months after owning the car. Come cold winter months, the brakes would squeak when depressed. Dealer changed fluid to a modified DOT3 fluid as per bulletin #PIT3779J.