What causes rotor damage?

[Mabuse]

My rotors are great, but I've had damaged rotors on previous cars and I just got through paying $900 to replace front rotors on my wife's car. What causes damaged rotors? What can I do to ensure that I never damage my rotors?

 

[CJ3Flyr]

There's two simple things that you can do that help dramatically:

1) When rotating the tires always torque the wheels properly.

2) After you come to a stop hold as little pressure as possible to hold the vehicle in position. Every few seconds let the car creep 6" or so. This is especially important following a panic stop or some other manuever that would cause high brake heat. I also use 'N' to help get my foot off of the brake. The concept is to cool the rotor as evenly as possible. By holding the brake pedal firmly your allowing a lot of the heat to dissapate through the brake caliper. The area of the rotor that's contacting the pads cools very differently compared to the rest of the rotor; this is why creeping ahead and/or using 'N' helps.

*CAUTION* That "little pressure as possible" thing: The cycling of the A/C may cause the car to creep. Don't stop, hold a light foot and end up bumping the guy in front of you because you looked down and I told you to hold the brake lightly. That would suck.

:cheers:

 

[khooper]

Our front brakes were making a grinding noise. The shop said our rotors were damaged by excessively hard brake pads, and replaced the rotors. They suggested we get the pads changed too. It is making the grinding sound again.

Is it the rotor really damaged?

Thanks in advance.
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[eskimochaos]

There's two simple things that you can do that help dramatically:

1) When rotating the tires always torque the wheels properly.

2) After you come to a stop hold as little pressure as possible to hold the vehicle in position. Every few seconds let the car creep 6" or so. This is especially important following a panic stop or some other manuever that would cause high brake heat. I also use 'N' to help get my foot off of the brake. The concept is to cool the rotor as evenly as possible. By holding the brake pedal firmly your allowing a lot of the heat to dissapate through the brake caliper. The area of the rotor that's contacting the pads cools very differently compared to the rest of the rotor; this is why creeping ahead and/or using 'N' helps.

*CAUTION* That "little pressure as possible" thing: The cycling of the A/C may cause the car to creep. Don't stop, hold a light foot and end up bumping the guy in front of you because you looked down and I told you to hold the brake lightly. That would suck.

:cheers:

I think 2 is a little excessive but I guess it is feasible.

Personally I think rotors would get damaged after heavy offroading where a lot of breaking was required then immediately doing a stream crossing. This rapid decrease in temperature could warp the rotors.

 

[004Gunner]

I've read before that rotors rarely warp but are frequently reported by mechanics to customers as something that needs replacing. I agreed with the article based on the construction of rotors and the everyday use they typically experience. From a mechanics perspective, if you are working on the brakes already, how easy is it to sell someone a new set of rotors, throw them on, and beef up the bill? :bs:

 

[CJ3Flyr]

I think 2 is a little excessive but I guess it is feasible.

Personally I think rotors would get damaged after heavy offroading where a lot of breaking was required then immediately doing a stream crossing. This rapid decrease in temperature could warp the rotors.

#2 may be excessive but I tow & am not afraid to use the brakes. I typically get well over 90k before my rotors ever transmit the slightest wiggle.

:iagree: on stream crossing with hot brakes.

Another thing that I have found to make a huge difference is following the break-in instructions for brakes. Yep, there's a procedure & the one about half-way down the page really helps.
http://www.egrbrakes.com/pdf/Break-In Procdure.pdf After my second stop I try to drive a little bit without using the brakes before shutting down.

:cheers:

 

[eskimochaos]

#2 may be excessive but I tow & am not afraid to use the brakes. I typically get well over 90k before my rotors ever transmit the slightest wiggle.

:iagree: on stream crossing with hot brakes.

Another thing that I have found to make a huge difference is following the break-in instructions for brakes. Yep, there's a procedure & the one about half-way down the page really helps.
http://www.egrbrakes.com/pdf/Break-In Procdure.pdf After my second stop I try to drive a little bit without using the brakes before shutting down.

:cheers:

I still respectfully disagree with # 2. I just feel that the breaks dont cool down quick enough to warrant the 6" slide every couple of seconds. Air does not cool metal that quickly - quick enough to cause distortion or warping.

WIll

 

[CJ3Flyr]

I still respectfully disagree with # 2. I just feel that the breaks dont cool down quick enough to warrant the 6" slide every couple of seconds. Air does not cool metal that quickly - quick enough to cause distortion or warping.

WIll

That's cool... :bigok:

For clarification (not that I am trying to change your mind); I mis-wrote. My 'creeps' are at 15-30 second intervals not every few seconds.

:cheers:

 

[Falls]

Sometimes I feel some brake pulsation , I think maybe they need to be turned. I hate to take it to the dealer since I know they will either say yes or I need a new set. I'm a hard on brake's .

 

[rook]

Excessive heat is the #1 killer. Some manufacturers go with cheaper rotors which will give out, warp and score under hard braking. The best way to prolong them is to avoid hard braking or situations where you "ride" the brakes. I cant count the number of times i see people gunning it from one traffic light only to brake hard at the next. Not only does this cause poor fuel economy, but the constant cycling, coupled with limited cooling ability in urban traffic will lead to worn brake components quickly.

Another contributor is drivers who use one foot for the gas and the other one fon the brake pedal. This type of driving will typically wear the pads first. If the pads get too low, the underlying material can tear up a rotor in no time.

Car and driver did a review of several different types of cars and how the brakes held up over several stops. The Infiniti FX's rotors took a beating. Looks like someone cut corners in the brake dept.!

http://www.caranddriver.com/reviews...ic_cars/tech_stuff_the_power_to_stop_feature/(page)/1

The focus of the article was brake fade, which is usually caused by excessive heat buildup, causing the brake fluid to boil, resulting in diminished brake performance. A good quality rotor will have the ability to dissipate heat quickly, primarily through the vents sandwiched between the rotors surfaces, and cooling passages from diverted air flow. An open spoke wheel design also helps keep things cool.

Some cars just go through rotors more quickly than others. Some oem rotors are not very good. Toyota trucks, in my experience have always had good rotors. A good quality rotor can last a long time and be resurfaced (turned) provided it is within the manufacturers spec for thickness prior to being machined.

 

[bzizzi]

Why did it cost $900 to get the front rotors and pads replaced on your wife's car !!! I have done tons of brake jobs and they are pretty easy and straight forward,and the parts with new rotors even good ones are around $80 each plus $60 for factory pads.
Brake jobs are the biggest money maker for repair shops and dealers !!!

 

[Mabuse]

$900 was the total bill for several problems on the car...I honestly can't remember how much the rotors alone were.