Brake system problems, master cyl. and rear brakes Options

[mikew04]

A few weeks ago I started hearing a squeaking noise from one of my passenger side wheels. It would be intermittent, so I figured it was my wear indicators. Around the same time, I would occasionally feel a vibration over 40mph like my tires were off balance. Checked the rear passenger brake assembly, and I could feel the heat coming off of it from 2 feet away. Okay, so my pads are worn and I need to get a rebuilt caliper.

Last night when I was coming home my brake pedal went to the floor. Pumped it again and got my brakes back; happened every time I used the brake last night. Same thing today, so im guessing its an internal leak in the master cylinder.

Today I put in new ceramic brake pads on the rear. The outboard pad on the passenger side (the side that the caliper that was sticking) was worn down to the steel, the inboard was down to the wear indicator. Drivers side were worn about halfway down. Finished up, got in my car to make sure they were working correctly and to break them in.

The brakes seemed to be working alright (besides the fact I had to pump the pedal twice,) however my rear drivers side wheel would lock up under a decent amount brake pressure, but the other 3 wheels would not (I think- it only seemed to be the drivers side rear, I do not think the passenger side rear was locking up as well.) I have never had the rears lock up on me like that, even while slowing the car down faster than I was today.

So.. im pretty sure I need a new master cylinder as well as a rear caliper for the drivers side; is that a correct assumption to make?
But what about my drivers side rear locking up on me like that? Is my proportioning valve on it's way out too?

thanks
-mike

[mikew04]

No, I did not bleed the brakes; only pads were changed. No leaks around the master cylinder either.

While driving last night after I posted, all my problems went away except for the sticking caliper. I'll replace that and hope those problems don't come back but I have a feeling ill be replacing the master cylinder soon enough.