I've got 34k on my rx and the dealer has replaced front rotors and brake pads twice already. Has anyone had similar problems. Could it be that the hub bearings are bad? Could it be the o-ring on the caliper piston hanging up, causing rotors to wear uneven? Lexus is not willing to replace rotors and pads anymore, but are offering a gift card of 150.00 towards service or parts, is this a good deal or should i question it a bit further?

 

Are you under warranty? If so, just keep on hassling them to fix the problem. $150 towards service/parts sounds like a money making scheme for the dealer. It could be many thing. Perhaps try another dealer?

 

Lots of things can cause a brake shake...

You ask if the caliper can cause it to wear unevenly, the answer is a most definite yes... but is that happening?

I can help, but I will need a little (a lot?) more information.

What was your original reason for having brake work done - was it shaking, were they just worn out, or was only one side worn out?
It sounds like the rotors were replaced - were they?
After brake service, did the shake immediately start? If not, how long after service?
If they turned rotors, did they use an on the car brake lathe?
Has someone measured rotor runout? How about hub runout?
Has the front end been checked? Tie rod ends, suspension bushings, ball joints?
Have the tires been balanced? Rotated to see if it goes away?
Last but not least, when do the brakes shake? I assume its only when applying the brakes, but at what speed is it worse? Do you feel it at low speeds as much as high speeds?

 

I had this problem back in 2005, and the car only had 19k. I took it in to my local dealer and they said yeap, your rotor are warpped, so they replaced both front brake rotors and new brake pads. Well now i have 32k and i have the same problem, so they are not covering this issue this time cause it's out of warranty, and the extended warranty doesn't cover brake rotors and linning. There is a tsb for brake vibration, but the problem is that all they do is put new rotors and brake linning, and i feel it doesn't address the root cause of the initial problem. They put same part number rotors and linning. I will get under the car this coming weekend and check all suspension parts and hub bearings and check for all loose parts. I took it to my local dealer and they already told me that the rotors had run out and that was causing my front vibration. My wife drives this car and she drives this car pertty easy. I also have transmission lag on this same car and they have done software updates twice with little help. It takes off faster now but the \transmission is shifting late. I will have to take it back in for this other isssue. Thanks for all the replies.

 

sometimes, when rotors are installed, there is too much runout, even on a brand new rotor... the spec on Lexus and most other vehicles is somewhere around .002" Anything more than this, and it may not shake when new, but thousands of miles down the road when pad material has been deposited and the rotor has been worn unevenly due to this runout... runout can be caused by improperly torqued lugnuts, dust/rust on the hub mating surface, etc...

the one way to ensure there is less than the spec of runout is to have the rotors turned on the vehicle, using an on the car brake lathe.... with an on the car lathe, we can get runout down to .0005 (there's an extra 0 in there) on-the-car lathes account for hub mounting runout as well...

 

Today i checked all my suspension and found everything nice and tight. I also ckecked my hub run-out and had none. when i went to check the rotor run-out i found the right side had none and the drive side had .0075. Also checked inner and outer tie rods and were found good. Checked lower control arm bushing and lower ball joint and found tight. Checked stablizer bar and connecting rods and found all good. I turned my rotors and when I went to remove old pad i found excessive brake material on the driver side. The brake pads on the right side were worn even, but on the driver side the outer pad was worn even and the inside pad had a quarter of an inch wear difference. The piston was hanging up on the release, causing this unever pad wear. The floating part of the caliper moves correctly with no hang-ups, that's why i'm suspecting that the piston on the caliper is hanging up to the release. Please pay attention to TSB BR004-04. Lexus knows that there is a problem with the brake vibration, but they are too cheap to correct the problem! So what they do is just keep putting brake rotors and pads and call it good when the root cause is not being looked into.

 

oh, well, thats easy - new set of calipers, rotors, pads and you should be set...

that rotor is almost 4x the allowed specification... it wouldn't cause a vibe on every vehicle, but some, if not most nowadays for sure...

who knows what the real cause of it - calipers should not go bad that early, but it wouldn't be the first time i've seen/heard of it...

 

Thanks for all your help. I look foward to reading more of this maintenace forum in the furture and maybe help someone else that might be having the same problems that i experienced. When I called lexus in torrence Ca. the guy that i talked to in the technical department didn't have a clue of what i was asking. He was unable to help me at all. I think they just hire bull****ters to give lip service. I really believe that lexus is aware of this problem, but they don't want to address this issue, so it's easier and cheaper to just change brake rotors and pads and call it good, and by the time the problem reoccures the car would be out of warranty. The dealer that I took it didn't have any measurements on there notes of the rotor runout. They noticed excessive pad material on the driver side of the inner pad, but didn't look any further. If they would have looked at the pad they would have noticed that the inner pad had uneven pad wear. I have an appointment on weds. so hopefully they can solve this issue under extended warranty. My tanny isn't shifting as smooth as it used to before they did a software update. Once again thanks for all your help.