SW17LS

Doesn't make sense that you'd have the same groan with all new brake hardware. Must be something else...

jfattibe

I'm gonna hold off. I'm not goin to pay $115 (ebay) for genuine Lexus pads and a shim kit and have the same thing happen. The Tech did say if the new Lexus pads didn't get rid of the groan that he would bleed the system. He said it possibly could be the problem due to me retracting the pistons into the caliper each time I changed the pads ???

Robb92914

I don't get it. Picked up my car from Lexus yesterday for rear door panels and control arms and they said the brake noise is normal and that my brakes are fine. I have to switch out my brake sensors today bc i didnt when I did the pads so will try to reinstall them. I feel like I only hear it on the driver side.

LuvmyLS

At highway speed, if you lightly brake, do you feel a vibration in the pedal or steering wheel?

Robb92914

Actually I do have a slight vibration when lightly pressing over 65...i didn't replace the rotors because Lexus said they were still good but thinking the might be warped?

LuvmyLS

It sounds like your rotors are warped. I have the same issue with my car. I'm going to bring it in to have the rotors cut at a shop that has an on-car rotor lathe. This ensures that the rotor is true to the hub.

roadfrog

That certainly is an option, but considering the price of quality replacement rotors (Centric Premium), I'd just replace them. Turning the rotors on a lathe will only remove more material and the warping will be quicker to return.

LuvmyLS

Here's a good article on the causes of rotor warping. The problem in most cases isn't really "warping" , but is the same effect due to uneven wear. The uneven wear is caused by either improper rotor installation or improperly torqued lug nuts. The on-car resurfacing will machine the rotor true to the car's spindle even if the hub or rotor had issues with running true when they were manufactured. Also, the on-car machining will completely remove any uneven wear, the so-called warping.

http://www.hendonpub.com/resources/a...etails?id=1787

As far as actual warping goes, it is quite unlikely that Lexus rotors warp due to heating and cooling. They are massive on these cars. To warp the rotor, you'd need to really heat it up. I'm talking cherry red. Then you'd need to quench one side of it to rapidly unevenly cool it. Also, Lexus LS brake rotors (like most passenger cars) use cast iron rotors. This material is very thermally stable and is not prone to warpage. Steel rotors, like on many motorcycles or some race cars, are more prone to warping, but not our cast iron ones.

Robb92914

Yeah I'm with you. Going to just get the Centrics rather than getting them turned. Thanks!

Lexuslsguy

You should at least sand the rotors to help the new pads bed. 120 grit. You can also use a rotor hone. Remove all the rust, new hardware and good brake grease.