Hey guys, first I want to thank you all for this wonderful forum and plethora of information available! It has been very beneficial! Ever since I got my 2013 Honda Fit Sport I've been crawling/lurking these forums for info.

Now to my question: there's a lot of hills where I live, and I was unsatisfied with the stock braking power of the stock rotors/brake pads so I decided to upgrade to StopTech drilled/slotted rotors. After the install I felt a much more noticeable "bite" in the braking and I was very much satisfied but I noticed that there's an uneven trail of brake pad residue on the driver side rotor, see pics for comparison:


Left is driver, right is passenger

I won't have time to check it out and see what's going on until this weekend - my question is how safe is it to drive like this? I'm worried about safety/damaging the rotor. I've never replaced brake pads myself so I don't know if this is uneven residue is normal for new brake pads. Will this eventually go away or should I double check my install job?

Thanks guys!

 

Well, for one thing, there's a rather deep groove in the driver side rotor (or two grooves actually)... did you get that checked out? It's likely that it was debris that got lodged in and caused that groove.

What it also caused, prevented the pad from properly applying even force on the rotor... the debris that caused the groove pushed the pad away, so the pad had more direct contact with the rotor on the other end. And since the pads naturally rub against the rotor even when not braking, you get wear no matter what... it's just more obvious when braking. So... light rubbing verses hard rubbing leaving streaks...

But that's just a theory.

Personally, I would either a, get new pads and rotors or b, take both parts (rotors and pads) to get them machined flat... this is to basically "reset" the surfaces to the way they should be... flat without grooves. Of course, make sure there's no debris anywhere.

 

Good advice above. Not sure if it's just coming through that way, but that looks to be a substantial groove.

 

Did you bed the brakes properly?

 

I'm curious when you say you upgraded to the PowerSlots but later say that you don't have experience changing brake pads. Those two things don't usually go together.

Did a shop change the rotors for you? Changing brake pads does take a little skill to make sure you don't contaminate the surfaces with grease, that everything is "free floating" when you're done so the pads is free under application of the brake and then backs off under release, and you use the proper torque specs so everything doesn't fall off going down the road. Otherwise your brakes aren't safe or will last very long without damaging the pads / rotor. If you think car / light truck brakes are hard, motorcycle brake pads have even more potential "free float" issues if not done "according to Hoyle".

As the other replies have noted, there appears to be very hard rocks / pieces of metal that have embedded themselves in the softer brake pad and are now gouging out those grooves in the driver's side PowerSlot. These hard rocks in the brake pad won't compress and not allow the pad surface to give you the 100% "bite" that you're getting on the passenger side = uneven braking to some degree. The bite will never get better as long as those two rocks are still embedded in the brake pad plus they will continue to act like a metal lathe and will continue to deepen / widen those grooves.

I would replace the pads / both sides of the car. If you replace them soon, I wouldn't resurface the PowerSlots unless you're concerned with the cosmetic appearance. Any resurfacing process removes rotor metal and shortens the remaining life and from my experience the rotor will warp more easily if overheated (mountain driving - on the brakes). With properly installed new pads, you'll never feel a difference from one side to the other because of those grooves. Actually, as the pad wears over those grooves, it'll create a high spot on the pad that will perfectly fit down in the groove and increase your braking power "microscopically".

Watch some vids and change those pads ASAP. .

 

Thanks for the reply guys! I really appreciate it.

@Goobers
Thank you for the recommendation. I'm going to look into buying new brake pads (if they are not salvageable) as these are probably destined for uneven wear because of the damage from this groove.

@Rob_H
I will re-do my brake job after watching the video! Thanks!!!

@spike55_bmw
I've "helped" my brother/father change brake pads in the past where I merely spectated the process but never did it by my lonesome. I've watched a number of YouTube videos (namely, , , and ). I had no idea about resurfacing causing premature warping, thanks for the tip! I'm not really concerned about the groove being there cosmetically speaking, I really just want better/more dependable stopping power. I will be replacing the brake pads, thanks for the info!

If you have any recommendations for good brake pads (I don't mind shelling out some decent money for them) I'll take any advice!

 

Some quality solid rotors such as Centric or KNS 4000 would have been a better option. In regard to pads. I autocross. Everyone has their opinions on what is good. I know national caliper autocrossers that use Stop-Tech street pads. Guys who run EBC, Ferrodo, Project Mu, Carbotech, Hawk, and OEM. Unless you're doing track days where the pads have to hold up to the increased temperatures I would say pick any performance street pad. It's really not that big of deal.

Drilled and slotted rotors is one example of where race car parts need to stay on race cars, not street cars. They are prone to developing cracks. On real race cars they are replaced after a race or at minimum inspected frequently. On a street car they're put on and used to the pads wear out or they fail. Google cracked drilled/slotted rotors for a cornucopia of photos.

 

I put PowerSlots on my pickup truck (truck long gone now) and with that size vehicle and the way I was using the brakes, the PowerSlots just didn't work for very long. They started to warp, I would get them resurfaced, then they would warp again in less miles than before. A viscous cycle to the bottom and eventual replacement with solid rotors. Again, it was a 6000 pound truck with a load in the back not a light-weight FIT.

Currently ('11 Sport AT), I coast up to most stop signs, turning situations, don't follow the car ahead of me too closely and my OEM pads (new on new car back in 2011) would have lasted to 70,000 miles but I was in a mood and changed them out at 50K because I was rotating tires, we were going into winter, and that's when my car gets its annual safety inspection (Pennsylvania). You don't want to be replacing brake pads in cold rain or sitting on snow. My wife is on her 5th set of brake pads (all 4 corners) on '09 CIVIC with 117K miles. If I'm a passenger, I almost need a 5-point harness to keep me in the seat when she waits until the last 50 ft to put on the brakes at a stop sign. No reason in the world for her to drive like that - she's not going to a fire, etc but she might miss that sale price on stuff we don't need.

 

I'm not inclined to agree here.

I swapped from OEM rotors to EBC slotted rotors at about 100k miles along with their brake pads and got noticeably better braking. But of course, that's not what the topic is about yet. After some 40k miles on them, I had to replace them because they were overheating (caused by switch from OEM style pads that created a lip to Wilwood pads sitting on that lip). They showed no signs of cracking.

In fact, if you do google, what you find are mostly results of drilled rotors. While I did find a few cracked slotted rotors, I also found just as many "blank" rotors that cracked the exact same way... ie, irrelevantly of the slots. Which to me, implies the cracks are more likely due to the rotors themselves being of poor quality... and that's kinda what you find with a lot of the older aftermarket drilled rotors too. In addition, very heavy braking on top.

You say Centric is one of the " quality solid rotors," And yet... just during the brake pad bedding procedure, they turned blue. It took 40k miles on my EBC with bad surface mating of the pads after two 80-20 hard braking to do cause my EBC rotors to turn blue. My OEM rotors did turn lightly blue in something like 25k miles, but that was more because I was trying to come down Pike's Peak in a decently controlled manner. While they did get hot, it wasn't enough for the guys at the check point to actually make me wait for it to cool down, even though I chose to wait anyway. After that, it never got any bluer, since you could see the exact imprint the brake pads left when I finally changed them at 100k.

The obvious overheating aside... I can also notice a marked drop in braking power. In normal driving, in means I need to brake sooner, which I can adjust for. The problem is, I've had occasions where f-ing idiots would come flying out in front of me, and without my EBC rotors, I know I would've slammed into them since I came within inches of contact. So the centric and there increased stopping distance is not instilling a whole lot of confidence in avoiding those situations.

 

Once again...I'm agreeing with you I'm a big fan of EBC USR slotted rotors. Not a fan of drilled unless they are high end rotors. Look at Porsche, Corvette, Ferrari, etc. Those factory drilled rotors have no problems, but they are also high dollar.

For street use, I think it's hard overall to beat quality slotted rotors. Two downsides are more noise and, I would think, slightly more pad wear caused by the "cleaning" effect.

 

The reason they are able to get away with such a wide variety, including OEM, pads is because autocross is very easy on brakes. There isn't enough time or speed to get real heat into the brakes.

 

I've only used the Centric Cryo-Treated rotors. Running stock/street classes in autocross doesn't allow for drilled or slotted torpors. I don't have any experience with the regular Centric rotors. I assume they are the same quality, just not treated? Overall my experience was good.

 

This I definitely agree with! I had one car that had a constant problem with rotors warping. It was a large, heavy car with large calipers, but the rotor diameter and thickness were not up to the task. Cryo-treated rotors solved the issue after trying a few solutions that didn't work.

They lasted in the 50,000 mile range while others were warping almost immediately.