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Just had a quick question to ask all of you. Me and my friend had an argument about whether or not you should replace the brake pads when doing rotors? Ik someone who has a brake pulsation and I was gonna do their rotors for them. But my friend said I have to replace the brake pads when I do the rotors. So do I have to replace the brake pads with the rotors? Or can I replace just the rotors since there warped? If the brake pads are worn Ill obviously replace them but the brake pads from what I know are in good condition. Thanks in advance!
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Responses on this are going to be split but I will share what I do on every brake job. First unpack the new rotors and give them a good going over with a stone hone, then I clean them with brake cleaner and hang them to dry. Moving on to the new pads I file to fit them loosely in their proper position to allow a proper fit, then I clean the calipers/ pads with Blake cleaner, lube the necessary areas and assemble. Short answer is I always change both to allow proper “bedding” of pad and rotor. As far as caliper slides I always machine polish the pins until they are perfectly smooth and relube them. On drum brakes I always change the hardware and wheel cylinders too. Brakes can be the difference between life and death and I never take risks with them.
There’s no hard rule on this. I can imagine pads I’d be willing to reuse and pads that are junk. Also, it depends on what the owner wants done. Obviously, the more new stuff you install the greater the likelihood of a good result and long service life.
I simply replace pads. I bed my rotors the very moment I have a new one installed, so they do last LONG time.
In general, bed-in consists of heating a brake system to its adherent temperature to allow the formation of a transfer layer. The brake system is then allowed to cool without coming to rest, resulting in an even transfer layer deposition around the rotor circumference. This procedure is typically repeated two or three times in order to ensure that the entire rotor face is evenly covered with brake pad material.
In real life, IMMEDIATELY after you had new rotors installed, you go to a long empty road stretch, touching brakes only gently, just enough, not to develop any local Thickness Variations in Transfer Layer. That’s the layer of brake pad material that imbeds into the outermost rotor surface.
Then, you accelerate to 50, and slam on brakes to bring vehicle down to about 15. Immediately accelerate again to 50 and so on. 3-4 times, until you smell the burning pads. Some will go to a long downhill and “drag” brake pads on rotors, using force of gravity to keep propelling the car.
Either way, idea it to get CLEAN rotor surface bedded with brake pad material, or so called Transfer Layer.
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