Replaced the rotors with cross drilled and slotted, and i picked up a set of porterfield r4s pads. The stopping power went down slightly, but the brake dust reduction is 80% or more. I'm happy with them, but I believe the rears are squeaking when I come to a stop. Were they installed improperly, or is there a reset procedure? something I'm missing? I did bed them in properly, and I believe they we're squeak free for about 2 weeks. unhingd?

 

First of all, the stopping power will continue to improve over time as you get some wear on those new rotors. Regarding the squeak, you may have to apply some hi-temp brake grease to the backside of the pad. That will acoustically dampen any high frequency chatter or vibration occurring between the piston and the pad.

 

I have had cross drilled and slotted rotors with Porterfield pads on for some eight months now and they have never squeaked or squealed, not even once.
Still a little bit of a "graunch" as I come to a stop, but it's nowhere near as bad as the stock brakes and goes away when the brakes get reasonably warm.
When I installed the pads and rotors I applied high-temp brake grease to the backs of the pads and the edges of the calipers (where the pads are placed), so as Lance says give that a try and it may fix your squeak.

 

Alright guys, im going crazy. Im still getting a bad squeek when the brakes get warm from the front drivers side only.

Ive taken the pads and rotors off, ground them down, removed foreign material
i used disc brake quiet, and applied grease to both the pads and slides as instructed... twice.

Any other ideas before I replace the pads first, then the rotors again? (new ones have less than 500 miles)

 

 

Roloc / Sand paper

 

You can try some CRC Disc Brake Quiet instead of using regular brake lube or grease. The Brake Quiet creates a better bond between the back of your pad and piston/caliper, you can think of it almost like a glue. Should quiet any squeaks arising from the installation of new pads. A bottle of it runs about $7 at Advance Auto.

 

New rotors need to be washed with soap and water or with brake cleaner. They still have the fabricating oil imbedded in the surface and abrasion will just grind in those oils. This spray is what I use on the rotors and the pads before I install them to remove any and all oil:





I then apply a high temp (3000 degF) ceramic lubricant (which has the viscosity of silicone sealant) to the back of the pads where they contact the piston and the caliper housing:



Also make certain all the backing springs/clips on the pads are spread out where they should be. These do get bent up in shipment.

 

There is a slight chance your squeak is caused by a sticking caliper slide pin, so if all else fails take the slide pins out, clean and lubricate them and refit. Also have a look/feel inside the plastic sleeves the slide pins go in, one/both may be dirty/clogged.

 

 

I installed porterfields using anti squeal lube on the back of the pads on my M3 six months ago and have not heard any noise from them of any kind. I don't think your problem is the pads...

 

I would also try going out and standing on the brakes hard, from high speed a couple of times to get some heat in them.

 

Yep, missed that one, the pads might be glazed and if so hammering the brakes a few times should de-glaze them.