OEM vs. Aftermarket Brake Rotors and Calipers

I thought the same when i had those rotors on my tundra living down a 2 mile unimproved dirt road that gets real nasty at times of the year which the town closes. Whether it be snow, slush, or mud i never had a issue with those drilled and slotted rotors. I've had similar rotors on my off-road race bikes when i did plenty of enduros, and xc racing. They were never an issue either, and they saw more mud, and spooge than most will ever see in their trucks.
When its time to replace the rotors on this tacoma, its a no brainer for me.

 

A tacoma is not a sports car...so resistance to fade is not such a big deal.

 

HAWK LTS pads and Brembo OEM replacement rotors. Just changed worn pads and rotors @ 102K miles. They don't disappoint. Used this combo on my old first gen that I used to 386K miles.

 

Depends on the load your carrying, or even towing a light trailer. You need good brakes that won't overheat, and fade. Although fine for these tacoma's as they come for everyday driving, imo, toyota could do a better job improving the front brakes on these trucks for heavier use.

 

Crossdrilled/slotted rotors aren't much of an upgrade. The reason they get rave reviews and everything thinks they help is because they're pulling off worn out stuff that wasn't working anywhere near it's potential, and installing new stuff...freeing up the pistons in the process, usually bleeding the brakes and flushing the fluid, maybe new hoses too, pads that are flat....of course it's gonna work better.

If we need more brake torque or more heat capacity, going to a larger rotor (4runner/tundra rotors/calipers) would be my choice. There are lots of pads out there that have a higher temp range than the OE, but in many cases...if the system in good working order, OE pads will be more than sufficient.

 

As did I on my 2006 Tundra. Not worth the "savings" at all.

 

Very few aftermarket rotors are an actual upgrade, most all are downgrades with flashy advertising. Avoid cross drilled rotors, they don’t help and only reduce the thermal capacity and structural integrity of the rotor.

Lots of info in the brake thread:
https://www.tacomaworld.com/threads/brake-upgrade-stoptech-rotors-trd-performance-pads.523829/

 

Nice write up. I worked for Centric Parts/StopTech for 18 years.

What you noticed with the vane count was simply a consolidation. That rotor has been used since the 2003 4runner non-sport. There are very likely 5 or more different OEM part numbers that have slightly different features but the same critical dimensions. We would compare new sample parts to existing numbers to see what the difference was, if anything...many times they changed the coating or something trivial. Other times we see different vane designs, and typically chose the design that is the most robust/heavy duty. The rotor with the vane count and style of vanes that matches the stoptech rotor in your pictures is the OE rotor for a 2003 4runner (I know, because I have one sitting here).

 

Interesting. Seems later StopTech reduced the rotor weight to more closely match stock 2nd Gen in a later part release. Some have been looking for a way to run the more robust rotors. I think people in that thread would find your comments very interesting. Mind sharing over there?

 

Sure, I'll copy/paste.

The company went through an acquisition a few years ago...they're now owned by First Brands, the outfit that bought Raybestos, Fram, Trico, and a few others...and everything changed. Caliper dept/customer service/tech support was moved to Mexico and most of the stateside staff was let go (me included) and our R&D facility shut down. I'm not sure where all our nicely organized sample shelf ended up...probably on pallets stacked in a warehouse somewhere in McHenry IL to be forgotten, or else I'd call someone (who doesn't work there anymore) to find them (on the shelf that doesn't exist anymore) and take pictures of all the different versions toyota has offered.

 

lots of misinformation in this thread.

i've played spectator of a few car forum scca sections. csg garage knows their stuff. brakes aren't as mystical or as cooling-oriented as everyone makes them out to be.

brake rotors don't warp.
take it from a company whose bottom line benefits from selling more brake components.
https://alconkits.com/technical-info/brake-tech/56-the-myth-of-warped-brake-discs

if your pedal is shaking, it means an uneven pad transfer from the pad to the rotor. it means either the rotors aren't very good, or you're in need of a different pad compound. i've seen the issues pretty regularly with powerstop pads for some reason with autocross guys. counterspace garage has made an entire company off suggesting alternatives to all the issues. i believe they build pads for a higher thermal load, and people aren't getting them up to temp, resulting in the uneven pad deposition on the rotors, though this thread sounds like a caliper issue more than a pad issue.

sungod was halfway there. drilled holes in rotors are supposed to provide an escape path for gasses under ultra-extreme braking. like you said, when everything is red-hot. the concept is at the n-th degree of brake usage, there's a layer of gas that 'can' build up that prevents the pads from contacting the rotor, and prevents braking. but it doesn't aid in cooling. and it's to the ultra level of braking that one would already have needed to upgrade to a higher temp brake fluid, altered pads, calipers, added brake cooling ducting, and likely have installed valving to alter the brake bias of the vehicle as well.

the cone-racing autocross guy's say this is superfluous, and they're on their brakes harder and more than anyone else in normal traffic, so i tend to agree. the holes in the rotors have roots in racing at tracks like nurburgring where racers are on their brakes for long hard extended times, building extreme levels of heat.

the slots are a different characteristic, they are there to wipe the pad, and provide a fresh layer of pad material to contact the rotor. this can increase initial bite of the pad, and makes for more consistent braking feel, at the expense of increased dusting and lower pad life. but that also doesn't alter the cooling of the rotor/caliper/pad combination.

stick with oem if you can, it will offer the best balance of every typical street-driving characteristic you'd want.

 

Agree with everything soundman said except that rotors do, in fact, warp. Take the next pulsating wheel you experience and before you take the rotors off put a dial indicator on it and spin it. You’ll find plenty of runout as the rotor turns.

 

so you're saying brake manufacturers and repair facilities making statements about how you don't need to buy what they're selling, are completely wrong?

https://www.google.com/search?q=war...69i59j69i65.4181j0j4&sourceid=chrome&ie=UTF-8

 

Not always, and if you do, it’s not usually the rotor, but the thing it’s bolted to

 

Not sure what that Google search is supposed to show, it takes me to a bunch of links about cryo treatment. I have my understanding from engineering school, designing, testing brake systems, racing and doing my own machine work for decades, not google. I say that with all due respect, not trying to pick a fight. Warped rotors show TIR which is total indicated runout. It’s the reason you turn rotors. You can actually measure how warped rotors are with basic shop tools.

 

you are saying usually your hubs are warped? Never seen that in 30+ years of doing brake jobs. Never even heard of that.

 

A dial indicator will read total runout

 

you're measuring rotor thickness, but you're not measuring pad deposits on the rotor. i think that's where the difference is. it is a different way of thinking about it, but starts making sense the further you dig into it.

the google link was supposed to be all the places saying that it's not the rotor, i was trying not to post a dozen links on the same topic

https://www.hansonsubaru.com/service/information/brake-myths.htm
https://www.motortrend.com/how-to/1808-nuts-and-bolts-warped-rotor-myth/
https://www.girardford.com/blogs/903/norwich-ford-dealer/why-do-brake-rotors-warp/
http://www.crossdrilledrotors.ca/blog/stop-the-warped-rotors-myth-and-service-brakes-the-right-way/
https://www.brakeandfrontend.com/warped-rotors-myth/
https://blog.fcpeuro.com/warped-brake-rotors-vibrating-reality-or-internet-myth

all these places bottom line would seriously benefit to spread the opposite--they'd sell many more brake components and fill otherwise-empty service bays. so the question i always ask is "if they're denying themselves the financial benefit, what benefit does the education offer to that company?" most of this info is online, so it doesn't entirely benefit them in a customer-honesty/relational way, nor does it promote a different product. one of the few answers i can come up with is that they're trying to offer an answer that solves a frequent customer question to alleviate some of the strain from their staff having to repeatedly answer that question that allows them to make money in more typical methods.



i ran across this in the autocross stuff, when the brz/fr-s was brand new in 2013-2015. as mentioned above, stoptech got bought out a while back. many new brz owners started autocrossing, and would always turn to powerstop pads because they'd been running them for years or because it's the go-to brand from the power of marketing. i suspect the buyout affected the composition of their pad in some way. a little while later, many returned with a pulsing brake pedal. changing the pads to a different composition always fixed it, sometimes not even changing the rotors-- usually they'd re-bed the pads with a pad-specific 60-0 procedure a few times, and never have a problem since. it's specifically how counterspace garage made a strong name for themselves-- helping people through those changes and recommending alternate pad options.

and when people stopped coming back after they altered pads, it became clear to me that it's less a rotor issue, and more a pad compounding issue.

i have some of this in my company work van(not my van, not my call to be changing pad compounds). sometimes light average stops after some highway use the pedal will pulse slightly. i simply drag the brakes for the next few stops to heat everything up, and the pedal pulses go away for weeks or months at a time depending on use. it does come back, but is pretty easy to correct for now that i know what causes it, and have an understanding of how it happens-- if the van had an out-of-round rotor, it wouldn't be so easy to correct, or maintain in this way.

i suspect if you took one of those warped rotor customer cars out, and did a few hard 60-0 stops to re-bed the pads to the rotor surface, the measurable runout you're seeing would either greatly diminish or go away entirely.

 

Everybody (well...some people) pull out a dial indicator to check the old rotor. It's incredibly rare that anyone pulls out a dial indicator to check a new rotor after installing it on a hub. If they did, they'd find a lot of problems before they become problems.

The other problem is rust. We can do the most perfect brake job...index the rotor to the hub and get to zero runout. Now we rotate the tires every 5K miles or so and the rotors get knocked around on the hubs a bit, causing rust (that always exists between the hub and the rotor after a bit) to move around and create a runout condition, which will eventually turn into a pulsation. So...now we have runout and a pulsation, but we still don't have a warped rotor. The high spots due to the runout have now picked up a different degree of friction transfer layer from the pads, or if an abrasive pad is being used...worn down a bit more than the rest of the rotor, creating a torque variation and/or a thickness variation.

 

I have never heard that the slots scraped the pads. Seems to me that if that were the case that you would be changing pads with every oil change. What I was taught by Raybestos was that the slots were there to allow gases to escape under heavy use to eliminate brake fade. Those gases on solid rotors keep the pads from contacting the rotor surface increasing stopping distance. I have no way of proving or disproving this, but that seems to be the popular rationale for the use of slots.

As for rotors not warping, that is total nonsense. I know this for a fact because I can put a warped rotor on a lathe and hear the cutter hit that high spot every time the rotor hit the cutter. I can also see on the rotor the metal getting cut the spot that was high. It is absolutely not some sort of build up. The fact that they actually put that on their website would deter me from buying anything from them. Anyone who has ever held a welding rod in their hand knows without a doubt that metal can distort when heated and rapidly cooling can enhance that effect.