[censored] from RockAuto and Centric

[stephen9666]

To the OP-

A bedding procedure could help reduce or eliminate the problem.

Perhaps you should read about proper brake bedding procedures from StopTech, the company that manufactured your pads.

Including this (taken from the StopTech website):
Quote:
The all-important transfer layer

As stated above, the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer , on the rubbing surface of the rotor disc. Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

Let's say that again, just so there is no misunderstanding. Uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.


More info at these links:
http://stoptech.com/technical-support/te...ures/bed-in-faq

http://www.stoptech.com/technical-suppor...rake-pad-bed-in

 

[HTSS_TR]

I had these German aftermarket rotors on my E430 and didn't have any problem: Balo and Zimmerman. They are a little pricy but not as much as dealer.

 

[MNgopher]

The Stoptech website is the one that always gets pointed to when discussions about warped rotors versus pad deposits comes into play. Considering that the brand of pads you've installed are from this supplier, I'd take very seriously their advice about bedding in your new pads.

My other question is you mentioned the runout measured was excessive. Was that with the rotors properly mounted? Would disc shims correct the runout issue as observed?

 

[SteveSRT8]

If you have a real runout condition it can many times be cured by "on-the-car" machining. This of course presumes that you did the work correctly and verified the fit of hub to rotor, etc.

As Centric AND Stoptech both say, rotors rarely warp. They simply get pad material welded into the iron. Sometimes bedding can help. I've cured many a pulsation with a quick trip to a back road where I can bed the brakes properly.

Many people here assume it's a rotor problem when it's really a pad problem.

 

[JZiggy]

I'm fighting a similar issue with my Civic -- even high quality rotors and pads develop a warp after a couple hundred miles.

I put on a set of freshly-ground rotors and measured 0.004" of runout. Yikes! This means that the hub mounting face itself has some runout. I bought rotor shims to correct it, hopefully that will work.

Don't give up on RockAuto yet... I've been using them for 3 years now and have been really happy with their prices and shipping speed. Even their shipping costs are usually lower than expected. I suppose for them to keep doing business they can't pay out every time an "economy" or "service" part that was made in China has an issue. But it certainly does raise the question, why offer cheap [censored] to consumers anyway?

 

[charbaby]

barlowc,

I have the EXACT SAME SITUATION...SAME ROTORS...AND ROCK AUTO!
SIDE NOTE: I have no ill feeling with RA. It's the Centric Rotors I have the issue with.

Springtime, 2011 I pruchaced 4 Centric Premium Rotors for F&R(painted hat/vents which Centric calls, Black E-Coating) and the Centric Posi-Quiet Ceramic Pads for our Mazda3.

By July 2011 there was a pulsation coming while braking. Centric Rotors are only warranty'd for 90 days. We were just past the 90 days. I called RA and the same thing was explained to me so, I am going to eat this one and just have the one rotor lathed(when I find which one it is).

The pulstaion is there and has not gotten worst what so ever. It's mild but, noticable(9 months now). When I dicover which rotor is out of round, I'll take care of it or replace it.

I have used Centric Brake Rotors/Pads for several years now(IIRC, they have only been in business ~10yrs) and they have become one of my favorite brands of brakes other than Brembo/Akebono. Centric's being less expensive. Price/quality were the original reasons I chose Centric and their rotors seem(ed) to last longer before warping/pulsing....LOL!

We just go one bad one and I'm not sure if this is going to sour me for life or not. Also, I am not liking the Posi-Quiet Ceramic Pads as the dust is awful black compared to other Centric Pads and others Ceramic Pads that I have used.

Other than the dust, the Posi-Quiet Pads are smooth/quiet with very good brake feel.

I really like the Black E-Coating on the rotors as they really help to keep rust away and look better much longer. I'll get the rotor issue fixed and we'll be driving happily!

 

[charbaby]

Also, I'd like to add that I have really been happy with the Centric C-Tec rotors and the Centric standard ceramic pads(no dusting) that I am currently using on my Altima(4 years now) with no issues. The Nissan OE just didn't last.

I first used this Centric combo on a Honda and a Plymouth and fell in love with'em and haven't turned back. So I do have a bit of experience and good success with Centric brake pads/rotors.

I am hoping that this is just a small quality issue that Centric is having and they clear it up soon.

I wanted to step up in the CENTRIC PREMIUM BRAKE catigory and it's only been OK thus far, not exceptional as I would have expected considering that I have had such good success with their lower line brake parts.

HMMMMM!

 

[stephen9666]

Originally Posted By: barlowc

The job went fine and everything seemed good initially, but a shudder developed and got to the point where my brother took it in to the dealer whose technician(s) concluded that the rotors were badly warped and had to be replaced.


How did the tech determine the rotors were "badly warped." Did they measure the runout? Did they give you the measurements?

If they didn't give you any measurements, my guess is that they just drove the car and/or visually inspected and said "probably warped rotors," which may not be correct.

I'm not one of those people who claims bedding is the answer to everything, but in this case it could help.

 

[barlowc]

Originally Posted By: stephen9666
How did the tech determine the rotors were "badly warped." Did they measure the runout? Did they give you the measurements?

They measured the runout. The official report just says "front brakes out of round", but when my brother spoke with them on the phone, he thought they'd said that runout was 4mm on the left and 3mm on right right, but that probably couldn't be, could it? That's big! So maybe it was 0.0003" and 0.0004", but that seems way too small for the shudder/pulsation experience. My Nissan was once measure to have 0.0011" of runout and that was just a minor pulsation.

Could all of this really have been caused by improper bedding?

 

[stephen9666]

Originally Posted By: barlowc
Originally Posted By: stephen9666
How did the tech determine the rotors were "badly warped." Did they measure the runout? Did they give you the measurements?

They measured the runout. The official report just says "front brakes out of round", but when my brother spoke with them on the phone, he thought they'd said that runout was 4mm on the left and 3mm on right right, but that probably couldn't be, could it? That's big! So maybe it was 0.0003" and 0.0004", but that seems way too small for the shudder/pulsation experience. My Nissan was once measure to have 0.0011" of runout and that was just a minor pulsation.

Could all of this really have been caused by improper bedding?


I think it could be caused by bedding. Even StopTech says so.

Since you don't really know the numbers, I'm not convinced runout is the issue, but it could be.

 

[barlowc]

Originally Posted By: stephen9666
Since you don't really know the numbers, I'm not convinced runout is the issue, but it could be.

I just don't know the numbers because I didn't talk to them, my brother did. They gave him numbers, but I'm guessing what he told me (i.e. 4mm / 3mm) isn't correct and was maybe just lost coming second hand. Knowing how this particular dealer operates, if they say they measured and found excessive runout, they did.

 

[mechanicx]

Originally Posted By: barlowc
Originally Posted By: E365
At what point did they develop the pulsation. First test drive? Days? Weeks?

It became noticeable within a week and progressed in an exponential kind of way.


What Centric said about brake pulsation being due to thickness variation is true, but if you had pulsation that soon then there is something else to blame besides thickness variation. Thickness variation takes time to develop usually at least a few thousand miles. There would seem to been a serious problem with the rotor, pad or maybe a large amount of hub runout. It might not be the rotor at fault, but centric claiming you have thickness variation that is not due to the rotor and refusing to even examine the rotors is a cop out and weasling out of warranty.

 

[1 FMF]

i bought rotors and pads from jcwhitney for my 1990 f-150 over 10 years ago. jcw advertised that the rotors and drums were ready to install and did not need to be turned prior to install, this was in their catalog before the internet. after having mechanic friend install them, the rear drums had never been turned initially it seemed, stepping on the brakes caused the rear of the truck to hop. So we had both the rotors and drums turned, reinstalled, and they were fine till years later i sold truck. i complained to jcw and wrote execs at jcw explaining what happened and sent receipts wanting reimbursement to having turned the rotors and i got it after about 6 months. with rockauto i doubt you will be able to even do that, they are just a distributorship and you will have to go through the manufacturer. My opinion just go get the rotors turned and move on, or go to carquest or napa and buy new rotors if it's not that much more than cutting rotors.

most rotor runout spec is 0.002" or less, and if you look at napa they sell ultra premiums with maximum runout less than 0.002", the premiums and others less than 0.004" which is saying these are cheaper rotors take your chances if you don't turn or measure them. if the runout spec is not stated then you take your chances without measuring runout.
In metric, 0.002" = 0.05mm, so less than 0.05mm or less than 0.04mm.

unfortunately you let the cat out of the bag and said you have used the rotors. your best bet would have been to return unused rotors to rockauto stating you measured runout on them prior to install and they are defective having X runout. I'm not exactly sure how credit card reimbursement works but in your case i would have to agree with rockauto, and somewhat with centric just because how brakes work and all the ways there can be problems other than the manufacture of the rotor. Only if you found runout prior to install and use of them do i think you have a leg to stand on if the credit card company examines the situation. And that would only be the case if you know you don't have a wheel bearing or flange problem. Are you sure your car doesn't use shims between the rotor and wheel hub? I've seen rotors for a mitsubishi from summit which came with shims that were required, never figured out why maybe something to do with correcting wheel hub problem i guess.

and warp is a slang term which really means a problem with lateral runout of the rotor.

http://www.centricparts.com/files/technical guides/brake-rotor-installation-tips.pdf
I agree with everything here except the point about pads requiring a bed-in. that is stupid, just drive normal and don't over brake causing excessive heat. they will wear in fine just over a longer period of time. you don't need to bed-in pads in one afternoon, it's not like the car won't stop if you don't. and if you need that kind of braking performance for a daily driver then brake pad break-in is not your problem, your driving is.

 

[KrisZ]

Out of round is not the same as runout. I would be cautious about the dealer and their claims. They smell a full brake job so their "expert opinion" is not without heavy bias.

 

[Ken2]

I have a very hard time believing that cast iron rotors warp, especially if they have cooling fins. Cast iron just doesn't usually move that way. I need to know if the rotors are installed on clean hubs with all the rust cleaned off. I need to know the runout of the rotor surface on clean hubs.

I've cured "warped" rotors by sandpapering the surface and switching to higher quality brake pads.

 

[NHGUY]

As a side note,Centric supposibly "Scorches" their better pads (Posi Quiet) after manufacture to almost cut the break in time to nothing.If they said you didnt bed in the pads,and used their pads,they are talking about of both sides of their mouths.

 

[ET16]

I was having run-out problems with a Taurus several years back. Being extra careful about even and correct lug-nut torque seemed to help.

 

[Trav]

Quote:
(FF is best).

HH is the best but realistically GG is probably the best commercially available rating.
Many Bendix CT+3 are GG rated.

 

[NHGUY]

Originally Posted By: Trav
Quote:
(FF is best).

HH is the best but realistically GG is probably the best commercially available rating.
Many Bendix CT+3 are GG rated.


I guess I was talking in general "auto parts store" level pads.I dont believe you will walk into a chain parts store and find any pad rated higher than FF....above that you are talking special order or race car stuff.

 

[1kickbuttranger]

What kind of break in precedure did you use?