brake rotors

[cndctrdj]

how long do the brake rotors usually last i these cars? ive got 16k on mine right now and they are warped. i had this problem on my old ta but i figured gm had fixed this stuff by now. anyway. my g rotors only lasted about 15k so it could just be a trend with auto manufacturers


let me know if this is normal.
also any aftermarket fixes like better rotors and pads or ss lines?
thanks

 

[Eric Smit]

I have almost 37k miles on my stock brakes.

 

[laborsmith]

I have not seen anything in writing. I usually get over 40K but not quite 50K. Yes I do from time to time keep a car long enough to get there.

Laborsmith

 

[cndctrdj]

well this might be a dealer fix thanks for the info
thanks

 

[RoXXXanne13]

time for ddm hook rotors

 

[cndctrdj]

time for ddm hook rotors

I was looking at them earlier. Has anyone used them?

 

[FloSonic]

Mine are all warped to hmmmm... I have 23k on them and the pads are still pretty thick. Saving my dough for better rotors tho.

 

[mitdr774]

Rotors warp from a number of things. One of the biggest is excessive hard braking. If you are a late braker the chances of warping a rotor go way up. I usually need two sets of pads before I need rotors. Even with taking the one car to Waterford Hills for a HPDE course and having Hawk HPS pads I cracked but did not warp some drilled rotors. Another big factor is when you get your brakes hot and go through a big or deep puddle and the rotor gets splashed.

 

[sx sonic]

Rotors warp from a number of things. One of the biggest is excessive hard braking. If you are a late braker the chances of warping a rotor go way up. I usually need two sets of pads before I need rotors. Even with taking the one car to Waterford Hills for a HPDE course and having Hawk HPS pads I cracked but did not warp some drilled rotors. Another big factor is when you get your brakes hot and go through a big or deep puddle and the rotor gets splashed.

Well said. I've had similar experiences and observations.

I'm at almost 30k miles now and my rotors are still fine.

 

[mitdr774]

I am at 23k miles and was shocked at how much pad is left. I am used to 25-30K from a set of normal pads. I feel as though i could go 40-50k on these pads if i keep driving the same. Quite pleased actually.

 

[ahtoxa]

Lots of misconceptions here as to what a "warped" rotor actually is.

On a normal street car that has factory brakes and it's not being used strictly as a track vehicle, it's not possible to heat the rotors to a point that they physically warp. What causes that pulsation in the brake pedal is microscopically uneven brake pad distribution over the rotor surface. As the brakes wear, some of the pad material will deposit itself over the rotor surface - again - on a microscopic level. When the deposits are made unevenly across the surface, you get that vibrating brake pedal.

In my personal experience, the best way to avoid this - in most cases - is to use a quality brake pad. Some pads are plain crap while others may not be designed for the type of spirited driving you are doing, even if it's just a few twisties here and there.

The brakes on the Sonic feel great 95% of the time, however there were a few instances where I was braking from about 90 for an upcoming hard right and the brakes have lost their bite until I was slower and they were cooler.

Solution: once it's time to do the brake, I'm going with Hawk pads and expect the issue to disappear.

 

[Stew]

Uneven tightening of the lug nuts can also caused warped rotors, even if you aren't hard on your brakes. Beware of shops that hammer them on with an impact wrench, they need to be tightened to spec with a torque wrench.

 

[FloSonic]

I'm suspecting the dealer of using the impact wrench...cuz its faster. I don't brake hard enough to get the rotors hot enough. Right now I don't have brake pedal vibrations... its the pulsating high pitch noise coming from the front when I brake at slower speeds such as driving in parking lots. (under 10mph)

 

[mitdr774]

Lots of misconceptions here as to what a "warped" rotor actually is.

On a normal street car that has factory brakes and it's not being used strictly as a track vehicle, it's not possible to heat the rotors to a point that they physically warp. What causes that pulsation in the brake pedal is microscopically uneven brake pad distribution over the rotor surface. As the brakes wear, some of the pad material will deposit itself over the rotor surface - again - on a microscopic level. When the deposits are made unevenly across the surface, you get that vibrating brake pedal.

In my personal experience, the best way to avoid this - in most cases - is to use a quality brake pad. Some pads are plain crap while others may not be designed for the type of spirited driving you are doing, even if it's just a few twisties here and there.

The brakes on the Sonic feel great 95% of the time, however there were a few instances where I was braking from about 90 for an upcoming hard right and the brakes have lost their bite until I was slower and they were cooler.

Solution: once it's time to do the brake, I'm going with Hawk pads and expect the issue to disappear.

As a former GM dealer mechanic, it is fairly common to actually warp a stock rotor. if it was this miniscule pad material build up you speak of, it would not take much to clean the rotor surface and be back to normal. However when it takes 10-15 thousandths of an inch per side or rotor surface removal to bring the two side of the rotor true again, it is quite clearly NOT pad material build up.

 

[ahtoxa]

It certainly is material builld-up. Even a relatively minor imperfection will cause the pulsating.

Here's more in-depth reading on this subject of "warped" rotors. Posted by stoptech - a rather respected name in brake performance.

-Warped- Brake Disc and Other Myths

 

[mitdr774]

A very small percentage of brake pulsation issues I had come in were from build up and of those the vast majority were rust from a pad that was not aggressive enough. When a rotor is 15-20 thousandths off as it rotates and when cut on a brake lathe only cuts a portion of the surface per pass, it is indeed warped. GM is known for specing a rotor that is just barely up to the task. It is really easy to overheat a lot of stock GM rotors without being on a track.

Get a rotor hot and then go through a puddle and it will also warp. I know this does happen as it has happened to me. Absolutely no pulsation before the puddle and a horrendous one after. That is most deffinately not build up on the rotor.

 

[$ub$onic]

I has warped stock rotors fairly easily, ( not on the sonic yet but on other vehicles). I have never actually seen material build up on a rotor that actually caused the same feeling of a warped rotor. I have also never have a rotor act up because of a impact wrench. A quick turn on a lathe will knock them puppy's right in though

 

[rabbs88]

My sonic just broke 14k and my rotors are shot too. Not sure if i should bother going to the dealer since it would be a "wear item".

 

[ahtoxa]

Rotors are likely going to be a wear item. I suggest upgraded pads and rotor resurfacing.

Not sure if I'm convinced that GM specs rotors that are barely meeting requirements. I've used the cheapest vato zone rotors in the past with good pads and haven't had pulsation issue. On the flip side, I remember using cheapest pads and having pulsation issues.

 

[mitdr774]

Maybe they changed how they did things, but in the past a lot of GM rotors were just above minimum spec when new and were fairly thin. By comparison the rotors on my Sonic seem very beefy to my Cavalier.

A warped rotor may or may not fall under the normal warranty.