I recently replaced my brake rotors and pads with slotted for rear and front. The old ones used to make the pedal vibrate telling it was the rear rotors. I replaced all of them with new ones from Amazon. Now I’ve recently noticed a slight shimmy which is only noticeable when stopping from high speeds. I think it’s because of the slotted rotors but I’m not sure. I don’t want to think that the rotors are warped like the original ones I had prior to replacing these. I’ve only put like 5 to 6k miles on the new pads and rotors so I don’t think they’re warped already. Can you tell me what could be the reason for the subtle shimmy at high speed braking?
The brake kits off Amazon tend to be cheaply made and don't last long. I've tried some from Amazon before, and they weren't good at all. When you installed the new rotors, did you wipe them down with some brake cleaner? New manufactured rotors are coated with anti-rust grease that needs to be removed before installation. And did you follow the "break-in" procedure for new brakes and rotors after installing everything? Slotted rotors do not cause any sort of pulsating when braking at high speeds...any rotor shouldn't do that.
I think after driving 5k miles, there should not remain any antirust coating on the rotors and yo probably have a low quality rotors. Change them.
I agree with Razmig. stuff from Amazon is of questionable quality. Since you replaced the rotors, you should have replaced the front wheel bearings and races at the same time. Also, was the correct bearing preload set when you installed the new rotors?
I agree, the wheel bearings may need to be looked at too since you have new rotors on and are still experiencing pulsation. It could be a bad rotor, bad wheel bearing or perhaps both...