Is there no way to avoid warping rotors?

[Carnoobie]

Originally Posted By: mechanicx
I don't know, if your pulsation came and went then maybe you did have some uneven pad depostis that others talked about. Or maybe one of the mechanics properly retorqued your wheels and that helped resolve the issue. I do believe that ceramics, while not harder on rotors, can leave pad deposits more than metallics. Run out can also encourage uneven pad deposits.

It appears you have 3 different mechanics saying three different things and maybe none of them really know what they're talking about. I'm kind of confused now, do you have persistent brake pulsation now or not?


2 of those 3 mechs I have ditched due to not being up to my standards.

I have pulsation but its light and only at certain points of braking. Like when im almost at a stop with the brake down, going slow and have the brake pedal down say 50%, I can then feel different up and down resistances in the brake pedal. But with light braking i dont feel anything.

Just want to make sure this is a pulsation im getting, how would you describe what you feel when you brake? Like when you have the brake down, will you feel the brake pedal increase and decrease in pressure against your foot?

 

[yonyon]

Originally Posted By: Carnoobie

Just want to make sure this is a pulsation im getting, how would you describe what you feel when you brake? Like when you have the brake down, will you feel the brake pedal increase and decrease in pressure against your foot?


Your car doesn't have a hydro-boost setup or an ABS system that generates that sort of feel, so yes that's "brake pulsation" or "brake judder." Does it also shake the steering wheel or just the pedal?

 

[Kestas]

Originally Posted By: Loobed
I think the biggest cause of warped rotors is the amount of chromium and nickle in the alloy. GM now uses some very low chromium and nickle alloy rotors to prevent warping, but without those elements, the rotors rust faster. GM made the decision that rusted rotors were better than warped rotors because most people won't see nor care about rusted rotors, but they can feel warped rotors every time the apply the brakes. Rusted rotors create less warranty repairs than warped rotors.

Not so. The low levels of chromium and nickel that may have been present before have a negligible effect on corrosion. I don't think they ever put more than 0.5% chromium or nickel in cast iron rotor alloy.

I can't comment on the warpage issue.

 

[Carnoobie]

Originally Posted By: yonyon
Originally Posted By: Carnoobie

Just want to make sure this is a pulsation im getting, how would you describe what you feel when you brake? Like when you have the brake down, will you feel the brake pedal increase and decrease in pressure against your foot?


Your car doesn't have a hydro-boost setup or an ABS system that generates that sort of feel, so yes that's "brake pulsation" or "brake judder." Does it also shake the steering wheel or just the pedal?


My car has ABS brakes.

No shake in the wheel, just shimmy in brake pedal.

 

[tig1]

Any time tour wheels are removed be sure the lug nuts are torqued with a torque wrench. This helps to prevent warping the rotors from unevenly torqued nuts.

 

[SteveSRT8]

Iron is iron, if the rotor is properly machined and fits right it won't matter who made it.

As stated several times previously, many here mistake a PAD problem for a ROTOR problem.

And while I agree that any pad deposition from bedding will wipe off in normal driving that DOES NOT mean that you should not bed your brakes.

 

[Carnoobie]

I talked to a mech of mine and he said my cars ABS brakes wont do this. Yes you do feel a noticable pulsation when the ABS kicks in cause thats normal. He said it is most likely rotors cause the pads cant do this unless they werent bedden in right, is that true?

He said to monitor if I get the pulsation after or before my ABS kicks in.

I know theres a general way to see if the rotors are warped and thats by doing the metal ruler trick and putting the ruler up to the rotor. Anyone else done this?

 

[exranger06]

Originally Posted By: Carnoobie
I talked to a mech of mine and he said my cars ABS brakes wont do this. Yes you do feel a noticable pulsation when the ABS kicks in cause thats normal. He said it is most likely rotors cause the pads cant do this unless they werent bedden in right, is that true?

He said to monitor if I get the pulsation after or before my ABS kicks in.

I know theres a general way to see if the rotors are warped and thats by doing the metal ruler trick and putting the ruler up to the rotor. Anyone else done this?


If the ABS kicks in, you'll feel pulsation in the brake pedal, not the steering wheel. If you're feeling pulsation in the steering wheel, that's a rotor problem, not an ABS problem.

 

[Vikas]

The ABS frequency is LOT higher than brake judder. Uneven rotor or pad deposit will cause the pad to move few times in a single wheel rotation but ABS electronic will be pulsating that pump lot faster than that.

In short, when ABS kicks in your will *know* it for sure! You can NOT mistake it for wrapped rotors and/or pad deposit symptoms.

 

[Samilcar]

When I've had ABS kick in, it feels like more of a "grinding" sensation (and sound). Much more high frequency than the pulsation caused by warped rotors.

 

[mechtech2]

You can try and 're index' your rotors.
Simply mount them 180 deg from where they are [or close].
Sure, you can measure with a dial indicator, test, and so forth, but this quick switch is 90% as good, and can fix things!
BTW, if it makes things worse, put them back where they were!

 

[Carnoobie]

Originally Posted By: exranger06
Originally Posted By: Carnoobie
I talked to a mech of mine and he said my cars ABS brakes wont do this. Yes you do feel a noticable pulsation when the ABS kicks in cause thats normal. He said it is most likely rotors cause the pads cant do this unless they werent bedden in right, is that true?

He said to monitor if I get the pulsation after or before my ABS kicks in.

I know theres a general way to see if the rotors are warped and thats by doing the metal ruler trick and putting the ruler up to the rotor. Anyone else done this?


If the ABS kicks in, you'll feel pulsation in the brake pedal, not the steering wheel. If you're feeling pulsation in the steering wheel, that's a rotor problem, not an ABS problem.


I dont feel any pulsation in my steering wheel, at all. And after some testing today, to be honest im not sure if this is pulsation or shimmy im getting. I think it might be normal.

Originally Posted By: Vikas
The ABS frequency is LOT higher than brake judder. Uneven rotor or pad deposit will cause the pad to move few times in a single wheel rotation but ABS electronic will be pulsating that pump lot faster than that.

In short, when ABS kicks in your will *know* it for sure! You can NOT mistake it for wrapped rotors and/or pad deposit symptoms.


I can now tell when ABS kicks in, before like months ago I thought it was a big warp in my rotor that caused it. The only question i have now is whether i get the pulsation only after the ABS kicks in. I couldnt tell today but will monitor again tomrw.

Originally Posted By: mechtech2
You can try and 're index' your rotors.
Simply mount them 180 deg from where they are [or close].
Sure, you can measure with a dial indicator, test, and so forth, but this quick switch is 90% as good, and can fix things!
BTW, if it makes things worse, put them back where they were!


I have to monitor some more cause to be honest im not sure if this is even pulsation im getting. I might just be thinking its pulsation when it might be normal.

 

[Vikas]

Generally, ABS will only kick in when one of the wheel locks up. This can happen when the tires are not brand new and you are in the rain or on gravel.

 

[Carnoobie]

^ so basically you have to slam on the brakes then.

I dont even know forsure if this is pulsation im getting, and i dont even think its from warped rotors but most likely just uneven pad wear or deposits.

 

[xBa380]

I never had a warped rotor with the three brake jobs I have done. All three jobs using powerslot brand rotors which have nice thick cooling vanes and look just as good, if not superior to the OEM rotors. Pads were 2x Hawk HPS and 1x Centric Ceramics.

All brake completely smooth, as they should.

Sorry to hear the problems you are having with yours. Seems like you got a lot of good advice/info so far!

 

[Kruse]

Originally Posted By: SteveSRT8
Originally Posted By: dparm
Rotors don't warp, they get pad transfer which leads to an uneven surface.

To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm


My pal, Dave Z! What a great guy. Fountain of knowledge and a Stoptech dealer and developer as well.
Many people mistake a pad problem for a rotor problem. Be sure and read these papers thoroughly as there are detailed instructions.
I have cured a lot of brake issues with a simple bedding that used to mean disassembly and new parts.


I agree that a lot of "warpage" problems are pad problems, but never say never.
While I do all of the mechanical work on my vehicles, a couple of years ago, my Aerostar had a sudden front wheel bearing failure. I limped it the nearest Indy and he replaced the wheel bearings and the rotor. All was well and I went on my way. The pedal was smooth and the brakes were good. About two weeks later, I got a pulsing pedal when I applied the brakes. I suspected the new rotor and when I took a large lug nut cross wrench to loosen the lug nuts, I could not get them off. (I'm 6'6" and about 250 and I'm not a weakling) I had to get a breaker bar with a cheater pipe to get the lug nuts off. Anyway, I machined the rotor and you could visibly see that it had warped, obviously from his super-duper impact wrench. I took enough material off that I probably need to put on a new rotor with my next set of pads.
Occasionally, it does happen.

 

[bigmike]

I had bad luck with my stock OEM rotors on my truck. On behalf of GM, I bought the truck used with 12k miles on it, so can't say for sure how the previous owner drove it. The rotors were horrible so I had them turned at the dealer (on their tab). They were pretty good for a few thousand miles and then started pulsating again and I dumped them for Powerslots, which are on the truck now 6 years later with the same OEM pads. I don't know how Powerslots are now, but back then they were making really good products.

 

[Carnoobie]

Originally Posted By: xBa380
I never had a warped rotor with the three brake jobs I have done. All three jobs using powerslot brand rotors which have nice thick cooling vanes and look just as good, if not superior to the OEM rotors. Pads were 2x Hawk HPS and 1x Centric Ceramics.

All brake completely smooth, as they should.

Sorry to hear the problems you are having with yours. Seems like you got a lot of good advice/info so far!


To be honest Im not sure if my rotors are even warped cause it might just be my ABS kicking in. Im still monitoring it but past couple days havent gotten any pulsation and braking has been smooth from light to hard.

 

[SteveSRT8]

Originally Posted By: bigmike
I had bad luck with my stock OEM rotors on my truck. On behalf of GM, I bought the truck used with 12k miles on it, so can't say for sure how the previous owner drove it. The rotors were horrible so I had them turned at the dealer (on their tab). They were pretty good for a few thousand miles and then started pulsating again and I dumped them for Powerslots, which are on the truck now 6 years later with the same OEM pads. I don't know how Powerslots are now, but back then they were making really good products.

If the rotors were slotted note this is done particularly to compensate for a PAD issue.

 

[lt1man]

Easy solution, DON'T BUY CHEAP rotors. Get a good pair of EBC rotors, forget about warped rotors. I some times brake hard or drive aggressive, with good rotors I don't have any issue.