slight shimmy

It seems certain roads and when brakes are slightly applied I get a little shimmy. If I apply the brakes harder it goes away... and it doesn't happen on smooth roads (which are getting fewer and fewer nowadays). Rotated tires and still does it so I don't think it's the tires out of balance. I used to have a four wheel drive and had to put on a shock to help prevent it with big tires.
Any ideas?

Warped front rotors.

Had a similar issue with my 2016.

While it could be front discs on yours, it also could be the electronic park brake controller not releasing the park brake prpoperly - that was what mine was. I noticed it happened more often after I had left the car parked with the EPB activated. i felt that the noise was coming from the rear. Dealer disagreed and replaced front discs and pads under warranty.

Noise still there, I pointed out the EPB technical service bulletin and they checked and my car was withn the VIN range. EPB control unit replaced, porblem solved.

Had a similar problem and thought I had a warped front rotor too. Put new brake pads on this Sunday (front and year). Shimmy went away. Weird...

bassman19111 said:

Had a similar problem and thought I had a warped front rotor too. Put new brake pads on this Sunday (front and year). Shimmy went away. Weird...

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nice!
it's possible the new pads were a little more abrasive, so they cleaned off the rotor surface a little and removed some uneven deposits that had been building up.

piotrek91 said:

nice!
it's possible the new pads were a little more abrasive, so they cleaned off the rotor surface a little and removed some uneven deposits that had been building up.

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Could be. The old ones were semi metallic that were on it when I bought it... (bought it used). I put on new ceramics. Thought I'd have a problem with the rear caliper pistons but that little cube tool worked great. All 4 wheel, less than an hour... Very smooth now!

Might give that a try.... could be pads as it only shimmies with light braking. Thanks

Could also be a sticky caliper slide pin. I had this happen once in life. Light braking and the sticky pin would not let the caliper move properly, heavier braking and the extra pressure would make it move as supposed to. Just a thought.

Thanks

I just came on the forum to see if others had this problem too! When I brake at speeds above 50mph (80km/h) I get a shimmy from the front end and the steering wheel rocks back and forth. Under 50mph its not noticable at all and when I am cruising at steady speed the car tracks straight without any issue and no steering wheel shake.

I'm assuming its a warped rotor issue and that it's likely only slightly out as it appears magnified at higher speeds. I have 70,000 KM (~43,000 miles) on it and they are the original pads. It's never had a brake replacement, but the dealer has done the "maintenance" (i.e. clean/lube) twice now. The calipers/rotors appear clean and I don't see any signs of unusual corrosion (this is just my visual inspection, I haven't taken anything apart!). My last service reported pad thickness at approx 5mm (4.5 on rears)

Is there anything else I should be looking at?

Bcdad182 said:

I just came on the forum to see if others had this problem too! When I brake at speeds above 50mph (80km/h) I get a shimmy from the front end and the steering wheel rocks back and forth. Under 50mph its not noticable at all and when I am cruising at steady speed the car tracks straight without any issue and no steering wheel shake.

I'm assuming its a warped rotor issue and that it's likely only slightly out as it appears magnified at higher speeds. I have 70,000 KM (~43,000 miles) on it and they are the original pads. It's never had a brake replacement, but the dealer has done the "maintenance" (i.e. clean/lube) twice now. The calipers/rotors appear clean and I don't see any signs of unusual corrosion (this is just my visual inspection, I haven't taken anything apart!). My last service reported pad thickness at approx 5mm (4.5 on rears)

Is there anything else I should be looking at?

Click to expand...

Nope. Have the rotors turned (or replaced-some here will say) and maybe throw a new set of pads on while you're at it and you'll be good to go.

Rotor Warp Something of an Urban Legend

Bcdad182 said:

I'm assuming its a warped rotor issue

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(bang) Please make it stop! Your rotors are not warped. You can fix this yourself !

While warping a brake rotor is theoretically possible, it is almost never the cause of pulsating brakes. What's really happening is that rotors can develop high/low spots and/or smooth/rough spots due to normal urban driving on brakes that were never properly broken in.

The high temperatures involved in uneven urban braking can actually cause the formation of cementite in the rotor surface - think spots of carbide mixed in with normal metal. If the brakes were not properly broken in during the first few miles of use, pulsating brakes are almost a certainty if you drive in stop/go traffic or use your vehicle in dirty/dusty environments.

If done properly, turning/grinding a rotor will sometimes remedy the problem (assuming you have enough material left), but only temporarily because the turning just cleaned off a layer of contamination on the thermally-altered rotor surface. If not properly broken in again and treated properly, the same problems will re-occur.

Sometimes pulsating or squeaking can be fixed by re- breaking in the rotor. What's required is to get the vehicle up over 60 MPH and gently apply the brakes taking as long as possible to slow down to about 10 MPH. Release and drive a short distance to cool down, and then repeat the process again at least 4 more times without stopping during each brake cycle. Some people advise repeating the process from top speeds dropping 10MPH each time.

I have broken in my brakes religiously on every vehicle and with every brake replacement, and have finally killed the warped disc myth for myself.

There's been a fair bit written on this topic. Here's a decent link to check out:
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths


FYI - At your mileage, you likely need new pads. As you noticed, modern braking systems actually wear out the rears first.

My CX-5 has 70k+ miles with original rotors and only new pads once around.

Thaumaturge said:

(bang) Please make it stop! Your rotors are not warped. You can fix this yourself !

While warping a brake rotor is theoretically possible, it is almost never the cause of pulsating brakes. What's really happening is that rotors can develop high/low spots and/or smooth/rough spots due to normal urban driving on brakes that were never properly broken in.

The high temperatures involved in uneven urban braking can actually cause the formation of cementite in the rotor surface - think spots of carbide mixed in with normal metal. If the brakes were not properly broken in during the first few miles of use, pulsating brakes are almost a certainty if you drive in stop/go traffic or use your vehicle in dirty/dusty environments.

If done properly, turning/grinding a rotor will sometimes remedy the problem (assuming you have enough material left), but only temporarily because the turning just cleaned off a layer of contamination on the thermally-altered rotor surface. If not properly broken in again and treated properly, the same problems will re-occur.

Sometimes pulsating or squeaking can be fixed by re- breaking in the rotor. What's required is to get the vehicle up over 60 MPH and gently apply the brakes taking as long as possible to slow down to about 10 MPH. Release and drive a short distance to cool down, and then repeat the process again at least 4 more times without stopping during each brake cycle. Some people advise repeating the process from top speeds dropping 10MPH each time.

I have broken in my brakes religiously on every vehicle and with every brake replacement, and have finally killed the warped disc myth for myself.

There's been a fair bit written on this topic. Here's a decent link to check out:
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths


FYI - At your mileage, you likely need new pads. As you noticed, modern braking systems actually wear out the rears first.

My CX-5 has 70k+ miles with original rotors and only new pads once around.

Click to expand...

Interesting article, I'd never heard of that before. Thanks.

Thaumaturge said:

(bang) Please make it stop! Your rotors are not warped. You can fix this yourself !

While warping a brake rotor is theoretically possible, it is almost never the cause of pulsating brakes. What's really happening is that rotors can develop high/low spots and/or smooth/rough spots due to normal urban driving on brakes that were never properly broken in.

The high temperatures involved in uneven urban braking can actually cause the formation of cementite in the rotor surface - think spots of carbide mixed in with normal metal. If the brakes were not properly broken in during the first few miles of use, pulsating brakes are almost a certainty if you drive in stop/go traffic or use your vehicle in dirty/dusty environments.

If done properly, turning/grinding a rotor will sometimes remedy the problem (assuming you have enough material left), but only temporarily because the turning just cleaned off a layer of contamination on the thermally-altered rotor surface. If not properly broken in again and treated properly, the same problems will re-occur.

Sometimes pulsating or squeaking can be fixed by re- breaking in the rotor. What's required is to get the vehicle up over 60 MPH and gently apply the brakes taking as long as possible to slow down to about 10 MPH. Release and drive a short distance to cool down, and then repeat the process again at least 4 more times without stopping during each brake cycle. Some people advise repeating the process from top speeds dropping 10MPH each time.

I have broken in my brakes religiously on every vehicle and with every brake replacement, and have finally killed the warped disc myth for myself.

There's been a fair bit written on this topic. Here's a decent link to check out:
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths


FYI - At your mileage, you likely need new pads. As you noticed, modern braking systems actually wear out the rears first.

My CX-5 has 70k+ miles with original rotors and only new pads once around.

Click to expand...

So I'm well aware of that line of reasoning and there probably is more than a little truth to it. At least the part about the rotors not actually being "warped", but having uneven deposits of brake material on them. Seems to me though, that the net result is the same in terms of ending up with an uneven surface for the pads to clamp down on and the resulting shimmy felt through the wheel. Most folks refer to this as warped rotors and, in my experience, the quickest way to eliminate it is to turn the rotors and (again) in my experience, it's usually a pretty permanent cure. The problem I have with these articles (and I've read a few of them all pretty much saying the same thing) is the insistence on the seemingly all-important "proper bedding" of the brake pads and all that that involves. In over 50 years of driving and doing my own brakes, I have never given two hoots about "bedding" brake pads and have never had a rotor warp or form cementite or what-have-you. I just avoid abusing new brakes for a few hundred miles or so and that seems to do the trick.

paris1 said:

....the quickest way to eliminate it is to turn the rotors...

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Good luck getting anyone to turn today's thin rotors. Like everything else, you'll be told to buy new ones.

If you've never bedded your brakes and have had no issues, then you are likely a smooth-brakng conservative driver and very lucky.

Most urban driving consists of unexpected stops that easily stress what are usually light duty brakes. Knowing how to remove the unwanted deposits and reconstitute the surface without turning is valuable knowledge for most drivers. YMMV