eightblack

We live in Colorado and our 2013 F Sport has around 12K miles on it. We went to Breckenridge yesterday for the day and drove I-70. For those of you who have driven it towards Breck, there's some decent long climbs and descents (6-7%) with plenty of truck runaway areas.

Anyway, as we were approaching Breck, on a steep descent, I noticed a very strong shudder/vibration thru the brake pedal and steering column. There was no fade and I couldnt smell hot brakes. The sensation stopped when we were on flat ground and when we stopped for lunch, I got out and as soon as the car had cooled down - I checked the front discs and couldnt see any glazing or sign of worn pads. The car was only serviced by the dealer at 7K miles (ie tires rotated, oil changed, etc)

It also happened on the return drive (out of Breck towards Denver). No warning light came on, and it was definitely a strong vibration only on pedal depression. Car is going to dealer tomorrow to be checked. This is our 3rd RX and I have never had this happen - and I have been a lot lot harder on the brakes on previous occasions.

Just wondering if anyone else has experienced anything like this? It felt like the discs were warped.

rayaans

Have you checked that the rotor itself isnt warped? This issue could be to do with uneven wear as well which the human eye cannot see. A good mechanic will use a micrometer on it

kitlz

eightblack, sorry to hear you're having problems. Have the dealer check the rotors for any defect. It happened to me on the 330 around 16K miles right after the tires were changed. I was braking on the drive home to take an exit and noticed the tires and steering wheel were vibrating. All of the rotors and brake pads were replaced under warranty. The service manager said something about inferior metal being used in the rotors. I don't know if that was true but the problem never returned. I'm familiar with the areas you were driving in. You definitely want the brakes to work properly.

Good luck finding a resolution and keep us posted.

dctex99

That is perfectly normal when you climb and decend a lot of hills; you just overheated them and they warp; if it did not go away the next morning, you badly overheated them and they are no longer true so will need resurfacing, or possible replacement. I am amazed it is not commonly known in Colorado????

eightblack

I am well aware of alpine driving, given that I have done it for 20+ years - both here in the US/Canada and Europe.

Spoke with the dealer today and front and rear pads needed replacing. In addition, rotors needed machining. All under warranty so no big deal.

This is just surprising - given that its the first time I have seen this happen. I wasn't hard on the brakes, I have driven multiple other cars on the same stretch of road without incident, the car wasnt particularly loaded (weight wise) and they never smelled hot. I detected no fade and no warning lights came on. This is my wifes car - so I dont even drive it on a daily basis.

Just a bit concerning thats all...but glad its fixed.

CometVR4

The brake rotors themselves don't warp. What you're feeling is brake pad material that was deposited onto the brake rotor surface which creates sensation of warping but it's just a area on the rotor that grabs more strongly than the other. It happens for instance exiting off highway with hot brakes and sitting at a stoplight holding the brakes. In the future just try rolling slowly instead of stopping.

viperdoc

I live just south of Denver and make that same trip multiple times per year, so I know exactly what you are talking about. Glad to hear they figured it out.

Thanks for the explanation CometVR4. I recently had to have the rotors on my Honda Odyssey resurfaced after I felt the exact same pulsations when slowing down on that drive to Breck. I was confused by the mechanic because he said the rotors "overheated". So, I asked if it was the brake pads then, and he said no. I asked if the rotors had warped, and he said no. So I was baffled. If he would have only said what you did, I wouldn't have badgered him for so long as to why I needed to pay $150 to get them resurfaced.

CometVR4

Yeah it's a common misconception because indeed it does feel as though the rotor is warped.

Cruiter

I had this happen on a past 2003 RX. The rotors did warp but the problem was caused by the dealer not properly torquing the lugs after rotation. The OEM disks are just about the best money can buy for that car. But given that, they can be destroyed by a careless mech. In my case, the dealer admitted it and replaced the front disks no charge to me. Evidently they had traced several similar issues back to one mech. He wanted to just turn them, but I said no they shouldn't have warped at the low mileage they did and the service mgr got or gave authorization to replace them. Now that was about 9 years ago.

I'd bet a dollar to a doughnut (current currency value vs doughnut may no longer match that expression) that's what 'may' have happened to you.

CometVR4

That is true as well. I've installed brand new rotors on my car and was in a rush so I used a air gun to tighten the lug nuts down. Bad idea because I got vibration right away. I was just saying a rotor itself cannot warp by heat generated from the brakes.