Finished this repair today. The resevoir on top of the master cylinder had a blackish sludge floating in the bottom with particulate matter. Removed, cleaned and let dry.
Installed new ATE master cylinder. A whopping difference. My pedal is much stiffer than it has ever been since buying the car. I can tell now that my rear calipers must have been dragging for quite a while - it just got progressively worse.
Wonder what this may do to my fuel mileage???
