Heavy vibration when applying brakes at highway speed

[jlcpremier]

My 2014 CX-5 has started developing a vibration/shimmy when I apply the brakes driving above 50 mph or so. I was due for an oil change so I took the car to the dealer. They said brake pads are still at 80%, but that I would have to leave the car with them all day to determine what the other cause might be. Before I do that, has anyone here run across this? Some Google research seems to point to an issue with rotors but with good pads should the rotors be having issues at only 40K miles?

 

[mazdadude]

My 2014 CX-5 has started developing a vibration/shimmy when I apply the brakes driving above 50 mph or so. I was due for an oil change so I took the car to the dealer. They said brake pads are still at 80%, but that I would have to leave the car with them all day to determine what the other cause might be. Before I do that, has anyone here run across this? Some Google research seems to point to an issue with rotors but with good pads should the rotors be having issues at only 40K miles?

A poorly installed wheel can warp a rotor at any mileage. The lugnuts and wheel are what hold the brake rotor on to the car. If the lug nuts are not torqued properly, the rotor can warp.

If it only does the vibration when applying the brakes, that points to the Rotor.

Another thing you can do to narrow it down further is to apply the HAND BRAKE slowly, gently, and lightly at the speed you feel a vibration. If you feel the vibration when using just a bit of Hand brake, that shows the warped rotor is in the rear.

 

[Anchorman]

If it comes through the steering wheel, its the front discs.

 

[jlcpremier]

I'll try the hand brake test. It's not just the wheel that vibrates, though I can definitely feel it on the steering wheel. It feels like the whole front end of the car shimmys, which makes me think it's the front rotors.

 

[KimGT]

check to make sure the calipers bolts are properly torqued down and tight, inspect the rotor for uneven wear (might not be obvious) and then reinstall the wheel and properly torque the lugs down in the star pattern.

Re-bed in the pads.

you can try changing rotors and seeing if that helps.

 

[hek8560]

ABS maybe? If I brake hard, the abs will kick in then that is when I feel vibration through brake

 

[minnesotaart]

ABS maybe? If I brake hard, the abs will kick in then that is when I feel vibration through brake

That's the way it's supposed to feel when ABS kicks in.

 

[deepfriedsushi]

Vibration when braking usually comes from an uneven deposit of brake pad residue on your rotors. This is generally known as "warped rotors", but the rotors themselves don't really warp. This can happen from overheating the brake pads followed by a cooling period where the car was parked, instead of moving. An example would be heavy braking coming off a freeway ramp, then parking the car shortly after. When the brake pad cools down on the rotor, brake pad material can be deposited, creating a "sticky" spot. So the next time you drive the car, the brake pads contact the rotor in both the "smooth" and "sticky" sections, which causes this vibration. This doesn't matter how much brake pad material you have left.

Stoptech has a great write up on this.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

I've experienced this first hand on my wife's 2010 Accord. I was coming off a freeway ramp which required fairly heavy braking. I could tell the pads were heating up because the stopping power got weaker and weaker even as I applied more brake pressure (brake fade). At the end of the freeway ramp was a stoplight, where I had to wait for a couple minutes. This means the overheated brake pads were only contacting one spot of the rotors and being pressed against them, depositing a bit of pad material on the rotor. Immediately after this freeway ramp, the next time I used the brakes, I could feel a slight vibration through the pedal. It continued to get worse over the following days and was only rectified after I got the rotors resurfaced.

Like others have stated, if you feel the vibration more through the steering wheel, it's most likely the front rotors. If you feel it mostly through the pedal, it could mainly be the rear rotors. Regardless, if you still have a good amount of brake pad life left, resurfacing the rotors (or replacing) should fix the problem. Then be weary of your driving habits to not over heat the brakes or give sufficient cooling time before parking the car. If you live in an area that is very hard on the brakes, you can consider upgrading to a higher performance brake pad material that has a higher operating temperature so it's less susceptible to overheating.

 

[jlcpremier]

Just thought I'd let you all know how it turned out. I put it off for awhile, but today just got my car back from the dealer. It had also developed a grinding noise from the rear right wheel when in reverse when the car had been sitting for a few hours, so I decided to finally address it. The shimmying was due to warped front rotors, so they resurfaced them. The grinding in the back was from my rear brakes which were down to .2 and had hit the sensor. The front brakes are still good though at .7 according to the dealer. I ended up paying $120 for the resurface and $300 for the rear brakes.

One thing that seems strange is how hard I have to push the brake pedal now to get the brakes to apply. Not sure if this is cause the pads are new, but i'm worried if I had to slam on the brakes for some reason, if they wouldn't react as fast and could potentially get me in an accident. Is this normal after new pads are put on? I would kind of think the opposite, where the slightest touch on the brake pedal would make the brakes react.

 

[Kedis82ZE8]

Unfortunately.... once rotors are turned there is less mass to dissipate heat so original issue can reoccur more easily.

I just replace my rotors at every brake job.

 

[yrwei52]

Unfortunately.... once rotors are turned there is less mass to dissipate heat so original issue can reoccur more easily.

I just replace my rotors at every brake job.

I also replace rotors at every brake job on our VW and BMW, but for different reason. Those European disc roters are really soft, and they couldn't meet minimum thickness requirement when each pads were worn out. I have to replace rotors and they're expensive too.

On the other hand, our Honda CR-V with 173,943 miles is on the 3rd front pads, but is still on original rotors! I turned the rotors each time I had the new pads as they're well over the thickness limitation. Amazingly the rear drum brakes are still original including brake shoes. Speaking about really low maintenance but still with excellent reliability!

 

[CX-5um]

Vibration when braking usually comes from an uneven deposit of brake pad residue on your rotors. This is generally known as "warped rotors", but the rotors themselves don't really warp.

^This. The term warped rotors get misused sometimes when the true diagnosis is brake pad material deposit baked unto the rotor. If the stock CX-5 pads are semi metallic (90% sure they are) then I would consider removing those deposits by doing some enthusiast driving/braking to get them off. This method is supported by said Stoptech link "In this case, simply fitting a set of good "semi-metallic" pads and using them hard (after bedding) may well remove the deposits and restore the system to normal operation but with upgraded pads."

If that don't work then have the rotors resurfaced. BUT they must be resurfaced correctly AND redo the bed-in process like for new pads/rotors. Otherwise the baked in deposits remain and the same issues will continue.
"The only fix for extensive uneven deposits involves dismounting the discs and having them Blanchard ground - not expensive, but inconvenient at best. A newly ground disc will require the same sort of bedding in process as a new disc. The trouble with this procedure is that if the grinding does not remove all of the cementite inclusions, as the disc wears the hard cementite will stand proud of the relatively soft disc and the thermal spiral starts over again. Unfortunately, the cementite is invisible to the naked eye."

That's why on a new car I follow the bed-in process and do moderate aggressive braking in spurts (but never complete stops in spurts) for the first 5k miles. CX-5 at 52k miles with lots of pad life and original rotors. Dealer last measured 8/10 on the pads front and back. We got lucky I guess. No sound nor no steering wheel shaking. At our rate my estimate is 90k miles before considering changing the pads.