Getting the most out of your brake rotors

[avguy]

Here's a first-hand story about Aveo lower control arms. Might have nothing to do with your rotor issues, but no harm in sending it your way.

Earlier this year I replace the LCAs on my '05, and a few weeks ago did the same on my daughter's '06 (who BTW lives in the SW corner of MI). After replacing her driver side LCA, I took it for a test drive. I immediately noticed a pronounced pull (actually more like a yank) on the steering wheel when I applied the brakes. Speed didn't matter - the pull was always happening. This had not happened half way through the job on my '05, so my first thought was that maybe I had unknowingly dorked up the backside of the rotor during the ball joint-to-knuckle install.

Took the rotor off and found no damage. So I went underneath looking for something else, and the only thing that I could see was lots of play in the worn rear bushing of the LCA that I hadn't done yet. So at that point I just changed the other control arm, and (as I was hoping) that noticable pull was completely gone and everything was fine.

So I'm relating this story because it clearly proves that there is interaction between the LCA and the brake system. Variable forces from one affects the other, probably in multiple ways. I'm certainly not saying that this is the root cause of your problem - I'm just a shade tree mechanic and don't know if worn LCA bushings/ball joint could cause the damage your rotors are getting.

But OTOH, my daughter's '06 only has 96K, and those rear bushing were in very poor shape (clearly proven when only one was replaced). And, given that the roads in Motown are probably not much better than the roads in her area, I would be really surprised if the bushings/ball joints in your '07 are still in great shape, given the much higher mileage on your Aveo.

I've used inexpensive rotors and have never had one go like your describing, so this is a head-scratcher for me. I'm not trying to say changing the LCAs will solve your brake issues. Just some food for thought about a problem that I don't understand.

[plant.one]

but i'm not experiencing any pulling to either side upon braking. just vibration. and every time in the past i've expierence this, changing the rotors has solved it. i should note that the LCA"s were replaced with the 100k service the previous owner did. they are not factory origional with 229k on them. so they may have around 135k tops.

i do plan to replace them.. however....

is the lower control arm able to change the geometry between the rotor and the caliper/pad assembly? i thought that all mounted into the knuckle assembly? ie.. the spindle goes into the knuckle, the rotor mounts to the spindle, and the caliper bracket mounts to the knuckle.... as well as the LCA and the upper ball joint/strut assembly.

it would stand to reason that if i had a LCA issue that was prominent i would see it in unusual tire wear, which i'm not. thats usually a good signal of a ball joint going kerflooey. but my tires are wearing smooth and even.


so back to my origional question - do you have any input on the rotors i posted ? is tehre any gain going to a slotted/cross drilled type rotor to help cool them down?

[petrified.rabbit]

AVGuy makes a good point of unsprung mass being enough weight to jerk you around on braking. If you feel only a vibration, I would guess the parts not entirely related. If it is warped rotors then it would be in the pedal, mostly. If it is in the steering wheel it would be more likely tie rods (inner, outer) or a caliper which pulls one side or the other. If the front end shakes, it could be a few things, suspension or something else. On the aveo specifically, I would check the dogbone mount first. The largest object that is going to be "stopped" from the brakes is the engine/tranny. The dogbone is the only part of the car that does this, and it is designed more to stop the engine from spinning on acceleration and move the torque to the wheels...

Your rotor wear in my opinion is because of the ceramic pads.. not because there is anything wrong with ceramic but because the size of our rotors, to the heat that ceramic runs at will just warp the rotor. Drilled, and slotted rotors won't help your situation because it only helps when your moving.. If you heat the ceramic pads up, they stay hot longer. Then when you sit in traffic, at a red light, etc, that heat gets transferred to a small section of your rotor. I have seen performance brakes with the same driving situation as you describe with little to no wear, but when you look at the rotor you can see brake pad shaped hot spots all around the rotor, and you could feel them when you pressed the pedal. Im not sure what to offer you as a solution, I can only suggest long steady stops, this will allow the pads to cut the rotor, and level out the heat. I used to have to do this before attempting to drive home from AutoX. I would get up to 35mph or so, and make 4-5 long steady stops to level out the feel of the pedal before driving home. Not scientific, but it worked for the most part.

I can't offer a replacement type of pad either. But if you are wearing out a rotor and only 30% of the pad as you say, your are over spending on your pads. You might as well step down to a lesser pad, save money, and hopefully that will result in a longer rotor life interval.

[plant.one]

ok. so let me say first - there is NO pulling upon braking at all - in either direction. never has been. the only symptoms that i experienced were vibration on breaking and some rotational noise as the bad rotor heated up in intense driving (and would rub because of it)

that said i did a major brake service this weekend. Pads (went to conventional pads just ot test it), warranty swapped for the same rotors i had (duralast gold), new slider pins/bolts, rubber boots and new caliper brackets.

after completion of the part replacement 100% of the symptoms are gone.


pad wear was even (both inner/outer and along the length of the pads) or very close - at least to the naked eye. some mild lines were evident both inside and outside on both rotors, but nothing to write home about.

driver's side slider pins were very smooth upon removal. drivers side caliper compressed with just my thumbs pushing on the piston.

passenger side one of the slider pins was a little sticky outward but would push in easy. the caliper piston was a bit more stubborn on this side - i had to put the pad against the piston and REEEEEELY squeeze to get it to compress. did not have to do the old c-clamp trick.

all slider pins were still showing evidence of plenty of grease, but it was very dark, almost black. possibly thermal breakdown combined with some road dirt?

if i had to guess, i would suspect that the passenger caliper starting to get a little tight along with that pin was part of the reason i experienced such a premature failure on the brakes this time around. i am going to source new calipers and replace them in the next week or two


and yes i'll have a mechanic examine the LCA's - they've got >30k on them since they were last looked at and i'm due for my pre-winter inspection anyway.

[avguy]

It's apparent that I didn't get my main point across about the LCAs. I wasn't intending to identify braking pull as a symptom. Before touching either those worn LCAs, there was no pull at all. The significant pull showed up after I changed one LCA only. And then the pull was eliminated completely when the other LCA was done. It was obvious from this sequence that the worn rear bushings in the 2 LCAs had an effect on the brakes, but also were somehow balancing each other, because there was nothing that I could feel in the brakes with both bad LCAs in place. So I was suggesting the possibility of some type of rattling or pin-ball effect of the 2 bad LCA bushings on the brakes. Again, that's just speculation on my part, and I only presented it because it appeared that your Aveo LCAs had never been changed.

[plant.one]

thanks for clarifying.

as noted, i plan to have my mechanic inspect them here with my pre-winter maintenance check.

[milesvinson]

Change the brake hoses. Those can get soft with age and can suck together under hard braking and then the caliper will retain hydraulic pressure causing brake drag. When this happens, the caliper will still collapse normally when you pull them off. Also a good idea to change those anyway. I never trust those hoses after about 100k miles. I've had them bust before. They're fairly cheap to replace anyway.

Also, I'd reccommend adding anti-drag brake clips to the pads/calipers. They're not available at Auto Zone but you can get them from NAPA and also ROckAuto.com. They are about $5. They definitely seem to help.

[MetroMPG]

Change the brake hoses. Those can get soft with age and can suck together under hard braking and then the caliper will retain hydraulic pressure causing brake drag. When this happens, the caliper will still collapse normally when you pull them off.

I had this exact thing happen to an old Accord (a car which ate brake rotors for lunch, BTW) and it drove me nuts trying to figure it out. I never understood how a line could "collapse" and pinch causing retained pressure, but it did.

[Dogman]

'07 aveo 5, 229k mileage.

I drive a lot. On average 3000 miles a month and sometimes as much as 1k miles a week. Often in heavy stop and go traffic on the expressway.

Needless to say this plays hell on my rotors. I find myself doing brakes at least once a year - lets call it 25-30k and im warping a rotor out and getting a split in the webbing.

I tried the new "premium" brake rotors from auto zone this last go-round, and they were worse. Like 16k and they're starting to warp already type of worse

ive been running ceramic brake pads for years now.


What i'm looking for are suggestions as to where i can go with rotor quality to extend this interval, will switching to something like a drilled/slotted rotor really help that much?

I'm looking at like going to something like these

http://smile.amazon.com/max-kt066981...words=ta066981


thoughts/imput from you high mileage drivers out there?

ive been using napa ultra premium rotors for some time. They last twice as long as oem and if they warp ~ theyre guaranteed for life. 😄

[edk]

I'm getting a little confused reading these posts. I have an '09' with almost 83k on it and I'm still on the original, rotors, drums shoes and pads. I drive somewhat aggressively, but I try to let the engine do all of the braking on the highway. Anyone else getting this kind of mileage out of their brakes?