Odd Brake Noise/Feel after rotor install?

[classicauto]

Pedal going to the floor = BADDDDD!

That is either (order of likelyhood):

-Master cylinder (wouldn't be leaking, the problem is the fluid bypassing the cylinder when you press the pedal because the bore/cylinder are worn, thus a low pedal with no or very little brake pressure)
-Boiled or watery brake fulid
-Bad caliper(s) (they would be leaking)


As far as whether any brake parts are sticky or not, DON'T pull the pads and have someone step on the pedal. You will likely shoot the piston out of the caliper with the removed pads. You can check the freeness of the piston a number of ways:

- Rotor and pad wear. Is it even? Are the pads tapered? Is one side worn significantly more/less then the other?
- Remove the caliper, compress the piston(s). Is one harder to compress then the other? One stuck?


I would be seriously worried about that progressive pedal though. The only way the pedal can reach the floor is either by a leak, or a worn master. And either of those spells imminent fail. If the pedal goes low, but you can pump it and it get stiff (and stay stiff!) there's likely air in the lines.

[infernosg]

I just wanted to update this thread. I swapped in some new Hawk HPS pads and Mazdatrix stainless steel brake lines on all four corners and flushed the brake system with some generic DOT4 fluid (Prestone, I think) and then bled it with a pressure bleeder. The noise I mentioned in the first post is now gone. I did notice the upper pad spring on the front driver's side is missing, the front shims were installed upside down by previous owner/shop (correct now) and the rear shims are missing completely, but I don't know if any of that has to do with anything.

That being said the brake feel still sucks. When the car is off I can pump them and they get nice and stiff, but as soon as the I start the car the pedal will slowly go to the pedal stop (not the "floor"). Based on this info, I'm with classicauto above; a bad master cylinder, so time to replace that next. Does anyone know how the AAS has anything to do with the MC? I see variants listed "with" and "without" AAS and/or ABS (I know I don't have ABS) but I don't know how it matters. The AAS has been removed/disabled on my car for a while now.

Also, does it matter on which side of the rotor the low pad squealers are located? I think stock has them on both sides but the Hawk's only have them on one. The previous pads had them on the inside of the rotors, which is where I put them, but given the information above, I have no idea if this is correct.