brakes shimmy, even after replacing rotors!

[string]

Hi,
My brakes shimmy on My 05 libby, even after replacing rotors and putting on ceramic pads on the front. it was fine for about 10,000 miles and now it is doing it again!!!
only noticeable when I am coming off the freeway for a exit ramp doing about 65mph. went back to My mechanic and talked it over with him and He says that turning the rotors again are probably the only solution.

any thoughts?

 

[TwoBobsKJ]

Hi,
My brakes shimmy on My 05 libby, even after replacing rotors and putting on ceramic pads on the front. it was fine for about 10,000 miles and now it is doing it again!!!
only noticeable when I am coming off the freeway for a exit ramp doing about 65mph. went back to My mechanic and talked it over with him and He says that turning the rotors again are probably the only solution.

any thoughts?

Turning the rotors probably won't help as the heat generated during hard braking from speed is causing thermal expansion of the rotors.

When installing new pads & rotors the system needs to be broken in to prevent the pulsing pedal. Few folks do it put if pays off big time. Basically the break in goes like this:

- 5 moderate slow downs from 25mph to 5mph pushing progressively harder on the pedal. No panic stops, just a gradual slow-down. Drive without using the brakes for about 3 to 5 minutes. Then...

- 5 more aggressive slow downs from 40mph to 10mph pushing progressively harder on the pedal. The last two slow downs should be quick to heat brakes.

After the second set of braking exercises park the Jeep for about 15 minutes to let the brakes cool completely then drive normally. Try to avoid hard, panic stops for the next 200 miles or so then you're good to go.

Bob

 

[rockymountain]

Also check the torque on the lugs.

 

[Jo6pak]

Check your outer tie rod ends

 

[colorado76]

Check your half shafts for play they could be bad. I had an issue with my rotors and pads, so my friend Harold changed them with a new set of Powerstop- dilled and sloted rotors and Powerstop pads. My problem is fixed, I paid $163.00 for the set online from Amazon.com.

 

[eradicator006]

Brake callipers could be sticking and causing the rotors to warp. I had this happen. It took 3 sets of rotors before the dealer finally figured it out.

 

[dude1116]

Check your half shafts for play they could be bad. I had an issue with my rotors and pads, so my friend Harold changed them with a new set of Powerstop- dilled and sloted rotors and Powerstop pads. My problem is fixed, I paid $163.00 for the set online from Amazon.com.

I think you and TwoBobs are running the same pads and rotors. Let me know how those do. I think those are what I'm gonna get when I have the money for brakes.

 

[tjkj2002]

Guess no one bothered to check the lateral runout of the rear rotors.

 

[NastyKnate]

i just replaced my rotors to fix this issue. if you only had yours turned and not replaced, jsut replace them. because you only feel it under heavy braking, coming off the highway (same issue i had) i would say its the rotors again. 10000miles on turned rotors is more than ive ever got.

 

[yellocoyote]

Original post said rotors and pads were replaced.

 

[NastyKnate]

he also says "turn them again". if he was clear i wouldnt have asked

 

[67Customs]

I have a 2005 and I had some pretty bad steering wheel shake upon braking. Same situation as you talk about. Exiting interstate about 65 mph, or going down a steep hill at higher speeds.

They stock pads eventually wore down and it was time to switch.

After quite a bit of research, I switched them to NAPA Ultra Premium rotors and Adaptive One pads. I did the break-in and everything. I also try not to let the pad sit on the rotor in one spot after long or hard braking so the pad doesn't leave deposits on the rotor that can "grab" the pad later while braking. I try to be pretty gentile on them. But, there is still some shutter there, albeit a lot less. Sometimes not noticeable.

My KJ has 60k miles and has been very well taken care of. Everything checks out. The ride is completely smooth in every other aspect of driving.

The moral of the story... I have no clue what causes it. I have kinda just learned to live with it as nothing seems to be wrong.

 

[streetglideok]

Did the mechanic/technician clean the mounting surface of the hub before installing new rotors and torque the lugnuts to spec? If one or the other was not done, then the job was not done properly. Any rust, or anything that is on the hub mounting surface for the rotor, will cause the rotor to sit slightly off, and create runout. That will lead to thickness variation and pulsation. Also, need to check the rear rotors for runout and thickness variation. That will cause problems as well. Poor quality rotors bought from some of the local parts stores are craptastically made and prone to it.

 

[67Customs]

In my case, I was the mechanic, and yes, I cleaned the mounting surfaces really well and I torqued everything to the specs in the FSM. The shimmy is only in the steering wheel, so it seems to only be the front brakes. And again, my rotors were NAPA Ultra Premiums and I've been told they are high quality.

 

[streetglideok]

If you feel it in the steering wheel when braking, then its likely in the front, but do not rule out the rears. I've seen wierder things then that transmit thru the steering wheel. Either machine the rotors, or go back and ask for a warranty on them, Make sure the slides and pad contact points are lubed with non-petroleum brake caliper grease too.