Good morning all! I have an 04 6MT tl with of course the Brembo brakes. Back in June I replaced the brakes with new OEM pads and rotors. Pistons in the calipers seemed to move smoothly and work great. Then after about 4,500 miles i started feeling my pedal pulsate, great warped rotor. So after a drive i felt the hub of the rotor to see which one could have warped. It was the drive front as it was waayy hotter than the passenger. So i did an inspection and found that it was the inside upper piston that was failing and you can see from the pad how it is worn unevenly. So to make this story short i purchased new seals and had them professionally rebuilt due to my rusted inner bleeder screws destroying the caliper threads. I did not replace the pads again but had both rotors turned since they were so new. Now my warped feeling is gone, but when i feel the rotor hub that driver side is still hotter than the passenger. It doesn't seem to be as hot as it used to get, but then again the weather is cooler here now. So i need advice or any input to how is this freshly rebuilt caliper is still causing more heat than the passenger side??? Bad rubber brake line? I have no rotor screws on that side but i have read countless threads with people who don't use them. I'm just at a loss. Thanks in advance



Inner Pad- Left side is worn lower

 

I would have replaced the pads too. You could re-lube the slide pins but if the calipers were rebuilt that should already be done. I would replace the pads since they were wearing against a warped rotor/failing piston, and see if that helps.

 

did you flush the lines and use new brake fluid? Check the slide pins and made sure that they move easily. I'd also install new brake pads. Make sure that the bleeder screw is 100% tight.

also check your brake lines for leaks.

 

Since the caliper been rebuilt to no avail, next step is to replace the caliper.

The pic of your worn pad above looks normal to me. Pads rarely wear perfectly even but, the heat issue is a real concern.

 

First, when cold, pull pads and make certain all pistons move freely.
Purchase an infrared thermometer, actually pretty inexpensive, and monitor the temps. When one is noticed hotter or not in line with the other, raise the car, remove wheel and try to push the pistons back into the caliper, if they don't move, open bleeders and give another try. If the pistons move in, line is bad.

The rotor screws aren't necessary as they are installed at the factory to hold the rotor stable during assembly.

The rotors don't warp, it's transfer of pad material that creates the buildup on the rotors causing the vibration and with the 4 piston calipers, normally it's the lower pistons that cause the problems as condensation lives in the lower part of the caliper.

Good luck

 

With mine it was the inner upper pistons that needed to be replaced on both calipers. Both calipers were completely redone (New seals, replaced and cleaned pistons). I have SS lines ill be putting on Monday to see if that is the cause and will also be having it inspected.I will be at a complete loss if this doesn't work. Not really the same thing, but i have this same issue with my yamaha yzf600r motorcycle. I replaced the pads, then my rotors pulsated due to one rotor overheating, i rebuilt the caliper and replaced rotors, that same caliper still dragging, replaced with SS brake lines and the problem still persists and the one caliper is overheating ruining my rotor. I have the worst luck with brakes. So i fear like my bike the brake line is not the solution, but ill update Monday.

 

Ditto on the slide pins, should been part of the reman.

I keep hearing the complete job was focused on just the pistons...

 

The Brembo calipers don't slide, they are stationary, so they don't have slide pins, they have pad pins and their only job is to give the pads something to hang from.

 

I didnt think those were slide pins since they just hold the pad in place. I dont believe that these are the issue either. Thanks for clearing things up. I just hope I can figure this out.

 

With that wheel off the ground, have a helper hit the brakes and as soon as they let off see if the wheel spins freely right away