Benton2016

Guys,

Could really use some advice although my vehicle is already in the shop and no one has really told me what the issue is. I bought my Lexus about 32 days ago which now has 699 miles on it. I have followed the recommended driving habits for the vehicle with regard to the brakes and driving habits. Unfortunately, as time has passed, I developed a shuddering when slowing down from 40 to 60 mph. I find it really odd that a vehicle with almost 700 miles on it would have brake issues but of course, stranger things have happened. I'm not an aggressive driver and do not race up to stoplights and stop signs nor make quick stops on the freeway. If anyone has any feedback, I would be very interested in hearing your comments. On the flip-side, I am driving the same type loaner vehicle and I am certain Lexus will make everything good.

Regards,

Dwayne a/k/a Benton 2016

bc6152

The first thing that comes to mind are the rotors. Usually brake shuddering is a result of warped rotors which occurs from excessive heat. The other thing is wheel balance that would occur at certain speeds. i.e. 40-60 mph. The best thing to do with a brand new car is what you've done. Hand it back to the dealer and the experts to determine the cause.

airgas1998

yep simple resolution....you have more than likely warped defective rotors. hopefully your dealership will replace them, and not turn them to make them true again.

mrsteve7

I recently had all four rotors replaced under warranty for this very shudder you speak of. The car was bought used and sat on the dealers lot for a number of months. The explanation from the Lexus service dept is that the rotors had rusted (as it sat) where the pads contacted the rotors, creating a "spot" at that location, resulting in uneven grab and hence the shudder. All is well with the new rotors.

5Ws

Random thoughts.

- As others have said, most likely warped rotors. Weird that it wound happen with so few miles.
- Could consider sticky slide pin on calipers, leading to uneven brake pressure and shudder.
- Defective or damage brake pads, usually associated with a squeal or grinding sound while braking (not always)
- Poor road surface, though you would know because it happens over specific strip of road.
- Defective tire is possible with slipping belt, though likely gunna feel that at low speeds too.
- Tire out of balance another potential culprit, though I would think you'd likely feel that as you accelerated, drove, or braked through the 40 - 60 mph speed.
- Tire alignment may be out. Steering wheel doesn't have to be off for alignment to be out.
- Then there's the whole ABS, EBD, and traction control thing(s), which could be from faulty tone ring or ring sensor or magic car electronic problems, but now I'm def out of my "shade tree mechanic" element.

Interesting problem. Is car still under bumper-bumper warrantee? Please post solution, if one is found. Thanks, in advance.

Richard

5Ws

That makes sense. Turning the rotors flattens out the contact surface. If the tech or mech does it right, he/she should "swirl" or "texture" the newly turned rotor, making it abrasive for the first few miles, which grinds off a little of the brake pad. That should resurface the brake pad, providing fresh/clean friction material, flatten out high areas, and allow for more contact with the rotor. If a "spot" was the diagnosis, then resurfacing the rotor should do the trick.

Richard

mrsteve7

I assume the rotors are not thick enough to resurface and would have been as the least cost option for warranty repair. All four were replaced instead.