Hello,

Just purchased a brand new 2024 Lexus ES 350. When leaving the dealership I was on the highway and had to apply the brakes pretty hard and there is a pretty substantial vibration, but after that it did not happen again and did not think much of it.

Since then when I apply the brakes with moderate pressure, when going maybe 50mph more there is a vibration in the brake pedal and like a light thumping sound. Disappointing this is happening on a brand new vehicle. Any ideas what this could be? I'm thinking I'm going to have to take it in to be looked at. I would imagine this would be covered under warranty, but for a new Lexus this is extremely frustrating. Thanks in advance for your responses.

 

I suppose it is the 350.
I am sure the rotors are warped. It is covered under warranty.

 

Yes it's a 350. Warped right off the bat? How can that be? is it common?

 

No, not common.
You need to baby the brakes on a new car, but you had to brake hard and that’s it. Do not tell that to the service advisor.

 

Appreciate the response, thank you.

 

I had that happen to me once on a brand new Honda Accord. Warped rotors after just a couple of hundred miles. Immediately replaced under warranty with apologies and no questions asked. Never happened again after that. I’m sure you’ll have no problem. But I’d get concerned if it happened again soon.

 

Im going to get it checked out Monday and see how it goes. Thanks for the response.

 

How many miles were on the car at delivery? Some cars arrive at the store from a dealer trade
that are commonly driven between stores. Usually driven by retired folks that are paid hourly and
take their time but occasionally it is a more strenuous experience on the brakes. There are also
opportunities for the store to be rewarded with "Program" cars - Golf Outing display cars. Most of
these are largely static parked on the fairways, but some are used by the Tour as Airport Shuttles.
Those get some hurry up driving styles. All to say that brand new un-tempered brakes driven hot
can warp. If the symptoms you describe continue you should be able to get them covered under the
warrantee.

 

Brand new brakes, regardless of the brand, need to “seat” or “bed in”, which is why they recommend gentle application during the first few hundred miles. In the real world, that is not always possible, of course. The pads/rotor might have been damaged enough by that very hard application before they were broken in. That is not a defect as such, and may be correctable. There are some articles on line suggesting make a repeated number of firm brake applications from a moderate speed (but not a full stop), perhaps 10 or so, which may help get the brakes back to where they should be. But they may still need adjustment or even replacement at the dealer in any event. The rotor(s) may be okay but the pad(s) may need replacement.

Either way, as suggested, I’d play dumb about how they got that way.

 

warped or perhaps pad material mucked up the rotors. Happened to me after roughly 30k and then again after a brake j9b w

 

warped or perhaps pad material mucked up the rotors. Happened to me after roughly 30k and then again after a brake job where they used crappy parts.

 

About 25 miles on it when I took ownership.

 

Dropped the car off this morning, my friend is the service manager at the dealership where I get our vehicles serviced. He said sometimes if the car sits too long in the weather here (South Florida) it can lead to some uneven spots on the rotors that cause the issue. Said it's not uncommon, dealerships are supposed to move the cars periodically to prevent this. Siad they are going to take the rotors and resurface them and that should correct the issue.

 

yep this is likely it. past decades i used to pound misconceptions on large car forums full of guys repeating the warped rotor myth. i even wrote a big page on it. it's not that rotors can't warp, it's for all intents and purposes short of tossing them in a furnace, they don't.

what happens is pad deposits for one reason or another. usually thermal limitations during excessive braking on tiny rotors, but in this case, a new car sitting forming little rust spots is likely the cause. in op's case, some spots caused shakes in light braking, and other heavier spots required heavy braking. essentially he's cleaning his own rotors in stages with various levels and degrees of braking.

 

Rotors can generally only be resurfaced 1 time depending how much is taken off. Very possible the brake pads will have to be replaced to correct problem also. It's a shame a new car is having to have this done. As for demographics this can happen to any car that sits no matter the location although more humid climates would make it worse. Look at your car after not driving a week and most likely rust will be seen on rotors. Constant not driving can cause the rust to pit rotors and also score the pads when pads clean the rotor.