VRCobalt

i recently got new brake pads, shoes, rotors, brake flush, and 4 new tires (balanced and aligned)

Here's the issue: If I brake from high speed, 70mph for example, I get bad vibrations between 65ish to 50ish. 40mph & below and 65+mph the brakes nice and smooth.

If I brake from 55mph, i get bad vibes til 50ish, from there down its smooth.

How come within this range, I get these vibrations. If the rotors were warpped, wouldn't it shake the entire time Im braking?

Thanks for any advice/info!

dead_black_balt667

i just recently had a problem like this as well. when you feel the pulsation, does the steering wheel vibrate with it? or do you feel pulsation in the pedal only? if your steering wheel is pulsating along with the brakes, then you can almost guarantee it's the rotors. if, on the other hand, you have no steering wheel pulsation, chances are the drums are out of round. I asked the forum about this and they kept telling me it was my rotors, and it just didn't seem right to me. i ended up spending $300 on new rotors and pads to find that the problem didn't leave. then i went to another brake shop and they checked the drums and PRESTO!!! $50 later my car was working like normal again.

JimzSS

sounds like you had the work done somewhere and most give a warranty. take it to them and just tell them it pulses at hiway speeds. it sounds like a slight warpage since at higher speeds you feel it and at lower speeds you dont. let them fix it because you spent your hard earned moola with them.

Halfcent

Actually, no. Rotors will in fact only vibrate at certain RPM's if they are warped. So that is a perfect symptom of a bad rotor. Take it back to whoever did the brake job and let them know.

SpeedJunkies07LS

my car does the same thing and the steering wheel shimmys and skakes well it does more of a shuter then anything but i think mine and your rotors are warped i need to save up and get new ones unles they are covered under my powertrain warranty?

Halfcent

Powertrain is engine and trans. Brake are part of your suspension, and are not even part of your 3 years 36,000 bumper to bumper. There is some degree of warranty coverage on brake parts, but it's limited. You have to look it up for your particular car.

SpeedJunkies07LS

yeah i have an 07 ls and its got like 39000 miles so yeah they saidmy warranty was up so i was like bitch haha

blackss2.0

my rotors were warped and only shook from high speeds down.

SpeedJunkies07LS

thats what mine do right now how much did or should it cost to get them ground

VRCobalt

Well I did the brake job, I bought bendix rotors from advance auto. Only problem now is that they dont stock bendix anymore, they gotta order and it'll take 1-2 days. And I have to give them the defective rotors before they can order them.

Question, if the rotors warp before manu 1yr warranty, are they considered "defective" or "normal wear"? Cuz 1 guy was giving me BS that I cant replace them because thats normal wear, but when I called a different advance auto the guy said its defective and they can replace them for free.

BTW, steering wheel does shake when brakes pulsate.

Halfcent

A warped rotor is not normal wear.

If you are going to replace them, there are TONS of options just here on this site alone. I use AC Delco performance drilled and slotted rotors from Crate Engine Depot.

If you are going to have them resurfaced, I think just about any shop can do that for about $50 bucks would be my guess.

FacelessKhaos

Yeah you can have your rotors "turned" on a rotor lathe.. but that will cost you between 50-80 dollars and they can only take some much of the surface off. If they go below .756 overall thickness, it's against the law to put them back on your car. Not so say that there aren't shops that won't do that (or that aren't people out there driving on paper thin rotors), but i know in NC if a notable brake shop does turn them down and they don't correct before that mark, then you have to buy new ones plus the cost of turning the other ones down, and that can cost up to about 300+ to get done. So, just buy new rotors, it's better and more cost effective that way. I have the same problem right now, just haven't ordered any rotors yet. But i do have some 5x100 (10 1/4") drilled and slotted rotors i'm trying to get rid of lol.

Jn2

iTrader: (1)

mine vibrate at certan speeds too, but thats b/c i need hubcentric rings for my rims:p

VRCobalt

I had already bought new rotors. Now that I know that warpped rotors are considered a defective item, Im taking them back and getting new ones. Thanks for the help.

SpeedJunkies07LS

yeah i think when the whel shimmys and shakes and the brakes pulse there warped and are there any 4 to 5 lug conversion kits out so i can get some ****** ss rims haha!

blackss2.0

they did it for me right at chevy. Took like an hour or two but it was under warranty

SpeedJunkies07LS

they did what at chevy??

pykie

My car use to do it at the same speeds as yours.
i took my car into the dealer they said oh your tires are out of balance, so i get that done, they were fine for a day so i was like what the hell, so i take it to a tire company this time around and they looked to see if anything, well the dealer did a shitty job on balancing them, they said and my REAR tires where chattered.
in other words one tread line would be high the next be low, so if you ran your hand from the top of the tire along the tread to the pavment or bottom you would feel the wavyness of the tire, so i got 4 new tires cause the front ones were bald and the problem is gone.
if you feel these vibrations in the car its self then its the tires they told me.


buy the ss parts. be about 1,000 bucks Canadian to buy them
and the conversion i seen was 1,400 canadian
but i forget the site.


who told you that?
i had rims on my car for a year with out them, then when i got my new rims this year cause i buy new rims every year they put them rings on my car, well after stripping 2 studs cause its so bloody hard to get the tire all the way on and seated right i cut them off and i still have no viberations

BigTizzle903

instead of getting them resurfaced, look into a pair of drilled and slotted rotors. the drilled and slotted rotors help dissipate heat much better keeping your rotors cooler therefore reducing the amount of warping. it's a little more costly but it might save you in the long run. (especially if you have a tendency of hard braking) THe only reason I still have non drilled/slotted is because my brakes have gone at 5k and 15k so they were still covered under warranty.

Maven

iTrader: (1)

The first thing you should do before returning your rotors is to remove them and make the hub face is clean of dirt/crap and free from rust buildup. Anything on the hub face will cause this problem. Its actually very common. The reason removing the rotors and cutting them cures the problem is becuase often times this simple act of taking them off and putting them back on removes the dirt between the two pieces. Just like its very co9mmon for electrical problems to go away after you disconnect the part to test it. The simple act of disconnecting and reconnecting the plug changes the quality of the connection.




This is isnt completely true. Yes slotted and drilled rotors have more surface and therefore more area from which to dissipate heat. they also have less mass(due to all the holes, cuts) and they cant absorb, or hold as much heat. So when you do get them hot, they stay that way because they arent efficient enough.

Brakes work because you turn motion into heat. in order to do this it has to have somewhere to go, the place it goes is into the mass of the pads/rotors. this is one reason why BIGGER rotors stop better, longer. Because they have more mass.

Also its a false presumption that heat by itself warps rotors. If this was true race cars wouldnt be able to move because there brakes would be so warped from the huge heat they store. Ever see a night time road race? Brake rotors glowing red hot? Pretty sure those rotors are hotter than youll ever got the ones on your Cobalt, and they still dont warp. Its because heat alone doesnt cause warping.


And of course lets not forget that drilling and slotting a rotor makes it weaker and highly prone to cracking.

SpeedJunkies07LS

hey guys do they make any way to convert my LS from 4 lug to a 5 lug???

Maven

iTrader: (1)

Yup, its called new hubs, wheels, calipers, rotors and mounting brackets.

SpeedJunkies07LS

HAHA smart ass haha but thanks ha

Maven

iTrader: (1)

No problem, and ive got a complete SS/SC rer axle for sale when youre ready to go 5 lug.