pulsing brakes

[FikseRxSeven]

i was wondering if you guys can shed some insight in my new problem.

i have 2008 cx9 with 18000 miles on it. maybe 17000 of those are on highway, so i dont use the brakes all that often.

i noticed that on heavy braking, usually between 60mph-40mph, the brakes pulse and the steering wheel kinda move back and forth, coordinated with the pulsing.

It is kinda suggesting warped brakes, but with only 18k miles on mostly highway driving, i'd like to think its something else.

any ideas?
could offbalance wheels be felt only on braking and not on regular driving?

 

[l-miwa]

Sorry, warped rotors is the most likely culprit. Have your dealer check them. They should still be under warranty.

 

[rk2112]

I have 14,000 and have started to notice the same thing. I mentioned it to my service rep and he said he could be warped rotors.

 

[Whitesnake]

What could cause the problem is OVERTIGHTENING of the lugnuts that can cause warped roters.. who has done your rotations? did they use the correct torque?

i was wondering if you guys can shed some insight in my new problem.

i have 2008 cx9 with 18000 miles on it. maybe 17000 of those are on highway, so i dont use the brakes all that often.

i noticed that on heavy braking, usually between 60mph-40mph, the brakes pulse and the steering wheel kinda move back and forth, coordinated with the pulsing.

It is kinda suggesting warped brakes, but with only 18k miles on mostly highway driving, i'd like to think its something else.

any ideas?
could offbalance wheels be felt only on braking and not on regular driving?

 

[FikseRxSeven]

the dealership has done all of the rotations.....

i cannot say for sure that they use torqued everything properly, cuz in the background when im sitting at the dealership, all i hear are impact guns (usually i cannot see my car).

actually, this makes me worry about getting it checked by the dealership since they probably caused the problem.... ill probably end up with the bill

 

[l-miwa]

Whether it was caused by the dealer torqueing it wrong or some other excuse they come up with, it should be covered. There really shouldn't be any reason that they should blame you for causing them to warp that fast. They are not a "wear item" like brake pads.

 

[cx9er]

I recently started having the same problem. I have 10k miles on my 9 I had it in for service so I had the dealer check it. They cut all 4 rotors and the problem is gone. Until this trip to the dealer my tiers were not rotated...So I guess heat caused my problem. Just an FYI, my dealer told me they will only cover brakes/rotors for the first year /12k miles

 

[Starter]

just had my front rotors turned, then they were replaced, now one day later the new rotors are locking up, squeaking and pulsing. Damn Ford crap.

 

[ZoomFive]

I reported my issue during an oil change 2 weeks ago. The dealer machined my front rotors indicating that they were warped. After that was done, the braking felt smoother, but the 60-30 braking still had the same wurble and slight shimmy in the front end. Make the car not so zoom zoom feeling and less confident. Been this way since day 1.

I have a follow up with a master tech in a week. Has anyone been offered a solution? Could it be a defective tire, warped wheel, bearings, spindles, tie rods, etc? I have very little hope that my dealer will find the problem, since they said they fixed it last time and gave teh car back to me.

There are other problems that many folks share on this forum... the coolant smell, the weak A/C, power memory seats that forget, bluetooth no responding, NVH at about 2500 RPM, and etc. If they can't address the wurble once and for all, I am going to feel that I made a mistake buying this truck.

 

[MacMaster]

Im having the same problem too, i noticed it like awhile ago, i have over 12k miles on my cx-9.. the driver's side mirror is still vibrating, power seats keep forgetting settings, and im going to feel that i made a mistake buying this suv too lol

 

[davecoyne]

Well, the 12 months/12k miles is on the wear and tear items like brake pads, rotors, etc. The dealer is under no obligation past those timeframes to warranty the wear and tear items, but if you are close or if you have a good dealer, you should be able to get some assistance.

 

[Craig-CX9]

Yup, same problem on an '07 GT AWD with 18,000 miles. My dealership replaced the front rotors due to warping under warranty.

Craig

 

[badself]

Yup, same problem on an '07 GT AWD with 18,000 miles. My dealership replaced the front rotors due to warping under warranty.

Craig

Rotor warpage can be a common problem even with high end marques, although it is more common and persistent with heavier vehicles.

Of course the composition of the rotor has a lot to do with it.

 

[Thaumaturge]

Rotor Warp Something of an Urban Legend

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, but only temporarily because the turning just cleaned off a layer of contamination and 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. 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/tech_info/wp_warped_brakedisk.shtml

 

[ZoomFive]

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, but only temporarily because the turning just cleaned off a layer of contamination and 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. 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/tech_info/wp_warped_brakedisk.shtml

Yeah... I broke mine in. I had detected a pulsing / shimmy when I picked up the car that got progressively worse. Even after turning, the problem returned. Guaranteed wurbling braking from 50-30.

 

[Thaumaturge]

Yeah... I broke mine in. I had detected a pulsing / shimmy when I picked up the car that got progressively worse. Even after turning, the problem returned. Guaranteed wurbling braking from 50-30.

If the rotors are really warped, you'll feel a pulse of varying frequency at all speeds with slower being more noticeable. At the higher speeds, the frequency gets high enough to be dampened sufficiently that it's tough to feel.

Pulsating can really only come from a malfunctioning anti-lock system or surface issues on the rotors unless someone really has distorted the rotor by using incorrect torque on the bolts. The only way to check for sure is use a micrometer and a straight edge across the rotor surface and by measuring for uniform thickness. It's tough or impossible to do this when they're still on the vehicle.

Were it me, I'd be insisting they replace the rotors with new as all the other fooling around is probably leading to the same fix assuming the anti-lock system is not doing something screwy (doubtful). I had a similar issue some time ago on another vehicle and new rotors was the eventual fix.

Like so many things automotive, your mileage may vary...

Good luck to you.

 

[ZoomFive]

If the rotors are really warped, you'll feel a pulse of varying frequency at all speeds with slower being more noticeable. At the higher speeds, the frequency gets high enough to be dampened sufficiently that it's tough to feel.

Pulsating can really only come from a malfunctioning anti-lock system or surface issues on the rotors unless someone really has distorted the rotor by using incorrect torque on the bolts. The only way to check for sure is use a micrometer and a straight edge across the rotor surface and by measuring for uniform thickness. It's tough or impossible to do this when they're still on the vehicle.

Were it me, I'd be insisting they replace the rotors with new as all the other fooling around is probably leading to the same fix assuming the anti-lock system is not doing something screwy (doubtful). I had a similar issue some time ago on another vehicle and new rotors was the eventual fix.

Like so many things automotive, your mileage may vary...

Good luck to you.

You and I in agreement on the above. I actually have a commitment from the dealer to give me new rotors. I actually think it is the tires and their construction. Although my wheels were rotated, I still feel the issue, but the wurble seems to materialize when I put stopping force on my tires. The pulsing in more in the steering and in the feel of the front suspension.

 

[Starter]

My rotors were warped, and they tried to turn them down, but the rotors were so out of round that they had to replace them. Now no problems.

done deal.