Cooder

BACKGROUND:

I have original brake pads and rotors and my car is 2.5 years old with over 50,000 miles. During oil change, dealership told me my front brake pads were down to 5%. I believe them because only recently have my brakes begun to squeal very occasionally, showing pads have worn down to the indicators. FYI, until this, I have never had any squeal or wobble, everything about the brakes has been fantastic for 2.5 years.

I have decided to go with the OEM front pads in order to maximize chances of no squeal. Decided not to go with the Hawk HPS pads because many on the Tire Rack website have reported squeal when the pads are not heated up. My original pads are NOT the updated OEM pads from the bulletin about squeal and excessive dust. I am not concerned about dust.

QUESTION:

Do I have to have the front rotors resurfaced along with front brake pad replacement?

I've read this forum and another forum for a different car as well as other websites and apparently there are 2 schools of thought. One is to always resurface rotors when replacing pads. The other is if everything has been going fine, don't bother because you might not want to take mass off the rotor unnecessarily. In other words, if everything has been going fine, then new pads have a high probability (or at least higher than otherwise) of working fine with no squeal or wobble.

Taking a suggestion from a website, I ran a ball point pen on the front rotors and there was no ink separation, indicating my rotors are pretty smooth without deep grooves. I went to a dealership and ran my finger over my front rotors and then did the same on a couple new RX8's on the lot. My rotors were almost as smooth. Because of this fact (and that I have had absolutely no squeal or wobble for 2.5 years), I was set on replacing the front pads and skipping the rotor resurfacing.

Later, however, I talked to an expert who said that the inner and outer edges of the rotors, as the pads wear them down, create lips that stick out, one on the inner edge and one on the outer edge of the rotor. He showed me on my car, and he was right (later, I checked the rotors on new RX8's at a dealership and, sure enough, their rotors had no raised lips and were flat all the way to the edges). In addition, he said that the rotor surface between the edges (ie., the area where the pads touch) appears to be pretty flat but is actually a little concave. He explained that the concavity along with the raised lips on the edges of the rotor in combination with new pads will cause uneven or excess (I forgot exactly what he said) heat dissipation that can warp the rotor. So are his points reasonable? Is the lip issue a serious concern? I find it hard to believe that the "don't fix it [the rotor] if it ain't broke" school of thought would fail to take the lip issue into account. Wouldn't new pads embed nicely after a break-in process regardless?

BTW, what is a reasonable price for resurfacing the front rotors (with labor and everything) not including replacing pads?

Marc_GS

Looks like you've put a lot of thought into this. Re-surfacing the rotors wouldn't be a bad thing, but I don't think anything catastrophic will occur if you don't. The only thing I recommend is that you bed in the brakes properly, since the pad will not perform optimally until it has worn into the existing grooves in the rotor (even if those grooves are small and shallow.)

Did you check the backside (facing inwards of the car) of the rotor as well as the outside? I have seen many rotors which look fine on the outside but are pretty rough on the backside. If this is the case, the re-surfacing would definitely be a good idea.

I had some rotors turned last year, for 15$ CDN per rotor. If you're in the US, you should be able to get a bit better than that in USD.

Cooder

Thanks for the reply. I haven't checked the backside of the rotor and will do it now. I had read that resurfacing rotors should be about $10 each and not more than $15. Is that with ALL labor? The dealership is trying to charge me $150 for resurfacing the two front rotors alone. That's why I would like to skip resurfacing if possible.

A thought just occurred to me that suggests the expert who brought up the raised inner and outer lips issue is not being completely truthful. It seems to me the only reason those lips exist is because the brake pad doesn't quite reach out to the edges of the rotor and therefore, in a sense, are nestled nice and firm between the raised lips. Wouldn't a new set of brake pads also nestle right in between the lips? This seems reasonable to me and might explain why none of the websites I checked ever brought up a "lip" issue. Why do they never bring the issue up? Probably because it is not a real issue, as long as the new brake pads fit right in between the lips. Seems like the presence of the lips (btw, they're about .5 mm tall) is actually a positive thing because it can help guide the new pads into proper position. Is my thinking wrong?

Go48

The dealer cost is primarily labor, but it is a bit high IMO. You could actually take them off yourself, take them to a brake shop and save $100 if you are capable of that, but labor rates for auto techs are very high as I'm sure you're aware.

Like Marc said, it's not absolutely necessary to turn the rotors when the pads are replaced unless there is uneven wear/warping evident. However, the pads will seat in better with the resurfaced rotors.

Cooder

Thanks for the input. I just called a bunch of places. Apparently the lip on the rotor can be an issue but not necessarily. Based on what a Mazda independent shop said, I will skip the resurfacing.

r0tor

iTrader: (1)

Your waayyy overthinking this... if your not feeling any vibration when you step on the pedal (indicating a "warped" rotor) you don't need to resurface the rotor

yiksing

There's only so many times you can resurface a rotor, if you do it everytime u change brake pads your rotor wouldn't survived. If under hard braking your brake doesn't pulsate, there's no need.

Im_DANomite

iTrader: (1)

you also need to remember, resurfacing a rotor is just putting a bandaid over a deep cut. all rotors have a minimum thickness spec. resurfacing the rotor just cuts the life of the rotor short. if your rotors aren't glazed over, warped, below discard spec, then i would just slap some new pads. any of the above mentioned...replace the rotors along with the pads.

Cooder

Yeah, I tend to agree with all of the last three posts, but you know there's that other school of thought. And they are insistent that you should get the rotors redone every time. The techs at the dealership come up with all kinds of factors that may or may not be legit. I'm overthinking it because so many "experts" are overthinking it.

Just to give you an example, a guy at Racing Beat insists that you should resurface every time. Racing Beat doesn't do service, so I figured his opinion could be taken as being without ulterior motives. But then I call Mazdatrix, who says I don't need to resurface, even though Mazdatrix does do service. So no manipulation there either, which was nice. But so the bottom line now is who is giving the better information? When I told Mazdatrix tech what Racing Beat (and others) said, he said Racing Beat doesn't do service so the guy I talked to wouldn't know.

ZoomZoomH

iTrader: (1)

dealer tells you to do resurface everytime you replace pads because resurfacing is ALL LABOR, aka ALL PROFIT for them...

it'll actually be cheaper when you have damaged/worn rotors to just get new rotors and put those on, after all, they are wear items just like pads...

ZoomZoomH

iTrader: (1)

oh, and bedding isn't necessary if you're just going to replace w/ OEM pads... the materials are similar enough between the newer/older versions that whatever's already on the rotors will work fine with the new pads.

Cooder

Exactly what the tech at Mazdatrix said and what some websites say.

Cooder

Awesome. This is what I was thinking as well, but I don't know anything so I wasn't sure.

KJ238

Endless brake pads 0-400degrees for the rx-8 rotors are pretty cheap and worth considering. They go for ard $220 here - ard $130 USD..
Just food for thought

Zin

Just had my car in to the dealership for the TSB break squeak. Of course they wanted to do the resurface, initially as a condition for pad replacement, then later changed it to a strong recommendation without which I will need much more expensive fix later. All this because they are not getting anything (from my pocket) for the TSB job. They said nothing about warping of the rotor, and I never experience pulsation during breaking, just the embarassing squeak at times.

Spent quite a bit of time reading, and this is the most helpful tread i have found. I will skip the resurfacing ($90+) eventhough the car is already in shop for the pad replacement and I am doing my 25k maintenance.

PS dealership id John Hines Mazda of San Diego

Delmeister

My car sat at the dealership for a couple of months because he could not get the starter replacement for the no-start issue. During that time the rotors apparently rusted, and as a good-faith gesture, he resurfaced them. The brakes had worked perfectly fine before this.

About 5,000 km later, I began to feel pulsations on braking which got progressively worse. The service manager claimed this could happen as a result of simply driving through a puddle of water and so refused to do anything about it. Mazda would not do anything because it did not authorize the work. I then called the owner of the dealership who told me to bring the car in right away for another 'free' resurfacing. That was about 4,000 km ago and no pulsations so far.

The rotor thicknesses before (after) the second machining were: LF 23.25 (22.65) mm, RF 22.92 (22.21) mm. Min spec is 16 mm. The rears did not need to be resurfaced.

So there seems to be lots of material on the rotors to work with, but I tend to avoid any unnecessary work because it can lead to things getting damaged or screwed up - some that will not become evident till well after the car has left the shop.

By the way, the service manual stresses that the rotors should be machined with an on-car lathe. My dealer does not have one of these.

ken-x8

IMHO, doing them on-car is a band-aid for the wheel bearing being a little off.

I once had brake pulsation on my Accord after having a wheel bearing replaced. Replacing the rotor didn't help. A friend (parts guy at a Toyota dealer) suggested on-car turning. I went to the Honda dealer. They checked the bearing and found it off. Replaced the bearing, putting the new one on right, and the same rotor that pulsed was fine.

I didn't see anyone else mention the other scam involved with "resurface the rotors every time." If you go to the same shop, then every second or third brake job they get to sell you new rotors. Especially if they set the lathe to take off a particular amount, rather than just what's needed to true them.

If the rotors are not scored or warped, then all that's needed is to break the polished surface with emory cloth. Go over the working area with a circular motion.

Ken

Rotator

Min. Spec for fronts is 22mm.
You are close to the limit.
Measure mine over the weekend with 60,000km - 22.78 - 22.85mm
Runout is zero.
No pulsation.

Did have a pulsation after a long trackday when a lot of pad material collected on the rotor surface - took a while for this to go away. They were the stock pads.

Delmeister

You are right Rotator! The tech wrote 16 mm on the notes he gave me