1996 Acura Integra, is my master cylinder out or something else?

[GrowthvsOil]

GSR 1.8 Vtech.
1)Two weeks ago coming off of highway brake pedal is low, pump it, brakes back, at stoplight after off ramp petal does NOT sink.
3)Changed front brake pads, did not bleed or open system, brakes fine.
4)One week later, cold day, pedal to floor, locks up at the floor, pulls to the right.
5)Brake still gets hard and holds while car off.
6)Bleed brakes, no change.
7)What am I?
Note: I have never had a problem with loosing pressure at stoplight.
Also what is the brake part at the front of the engine at the end of cable with bleeder screw and large rubber boot that is torn and squeaking when brakes pumped. What is the name of the part?

 

[Roger]

torn and squeaking? that is not good, and you likely found your problem, sounds like a dust boot? possibly is torn too. Im not familiar with audi but I know a brake problem when I hear it. This is not going to be a cheap fix so be sitting down when the repair bill comes, expensive import car parts are going up, and up and up, as the price of fuel rises, everything is going out of sight. The car should have been in the shop 3 weeks ago, you were lucky you did not lose the brakes.