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Brake Job Gone Bad

Old 03-14-2019, 05:41 PM
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Funny how they don't tell you this at the dealer with brand new zero mile cars
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Old 03-14-2019, 05:43 PM
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I always use old pads to bed new rotors.
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Old 03-14-2019, 06:10 PM
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Originally Posted by wc11
Funny how they don't tell you this at the dealer with brand new zero mile cars
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Old 03-15-2019, 01:34 PM
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Originally Posted by jfort View Post
found this on seems reasonable. thoughts?

Brake pad bedding is an important process that removes impurities from the surface of the brake pad and lays down a thin layer of pad residue on the rotor surface. This is accomplished through repeated heated and cooling during braking. These cycles are like Goldilocks and the three bears: temperatures need to be just right to prevent scarring of the brake pad and rotor surfaces, or uneven pad transfer. Follow these easy guidelines and enjoy quiet, smooth and long-lasting braking. While every manufacturer has a different method for bedding in their brake pads, the basics remain the sameóregardless of brand.
  • Find an open stretch of road that will allow you to safely stop your vehicle multiple times
  • Accelerate to 35 mph and apply moderate brake pressure to reduce your speed to 5-10 MPH
  • Repeat this process 3-4 times, the goal is to warm up your brake pads
  • Now turn up the heat even more by increasing your speed to 45 mph and braking down to 10 mph
  • Repeat this process 3-4 times
    • Pro Tip: Itís important to avoid coming to a complete stop during this stage as itís possible to melt brake pads against hot rotors. Of course, should a deer, pedestrian or Sasquatch run onto the road, feel free to mash the brake pedal. Safety first!
  • Your stop-and-go session is now complete. Park the car and allow the brakes to fully cool for an hour. For best results, avoid pressing down on the brake pedal when parked
While bedding in your brakes can sound like a sensitive procedure, one funky stop isnít going to ruin your efforts. Gas-off and heat will occurr. Drive safely and avoid emergency stops, if possible.
This is the exact process I use, but add a 3rd set of stops from almost stops from 60 or 70 mph, then the cool down drive from my bedding loop is about 3 miles where no braking is required. What probably makes you feel like their warped is that since they weren't bedded properly, you have uneven material transfer on the rotor from the pad material. The pad material to pad material on the rotor relationship is actually what give you that nice initial bite when you apply the brakes. In your case, you have some pad material properly bonded but other places where it's not or there isn't any, so as the rotor turns your getting a grab / release / grab / release effect which feels just like a warped rotor.

The rotors need to be fully cleaned from the current pad material - brake cleaner on a roloc pad on a drill is how I do it (it slings so do it outside with an old shirt on), then sand or file the surface of the brake pads (wear a respirator). The goal here is to get to a fresh layer of pad material that isn't already glazed - doens't take much - you want the shininess gone. Put it all back together and then bed them using the process in jfort's post and you should be good to go. Make sure to use either the OEM pad dampeners or an anti-squeal past on the BACKSIDE of the pad, not the friction surface. This will keep them nice and quiet so you don't get squeal when stopping.

If you need to bleed the ABS actuators and don't have a Durametric, you can just find a road with some loose dirt and do a few panic stops where you feel the pedal pulsing as that's the ABS pump working and will move the fluid through. A new home construction site is usually a good place where the trucks going in and out have left a bunch of dirt in the road.
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Old 03-15-2019, 07:08 PM
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Go to the StopTech website, which evidently is now APCAUTECH.COM. ( Head to RESOURCES and then WHITE PAPERS. At the bottom of the first page are 3 white paper articles that do a good job explaining the bed in procedure. Start with the BED-IN THEORY paper then read through the stock and performance papers. These are pretty good write ups and help you understand the bed-in process. I've followed these guidelines for years and have not had any problems. Good luck!
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