yup, rotor blanks vary in quality

[meep]

Just installed new front brakes on the tundra in my sig. Used raybestos at-300 rotors with machined slots, along with akebono pads. this combo has proved excellent in my wife's MDX, with a lot more braking power and headroom than before, absolutely amazing performance.

These rotors are pricey. Best you can find i ~$90 a corner up to $210 depending on where you look. They have a bit more thickness to the braking surfaces, with slightly less gap in between, or at least they appear that way in pictures.

The install was cake and this truck is 99% rust-free, so there were no surprises during the install.

Tremendous judder however, immediately after installing. I figured it was my error. took it all back apart and looked for trapped rust, poor rotor seating, and even took a sanding block to scuff them up. One of them had an arrow-straight hairline crack all the way across the braking surface on the front, and a dimple surrounded by raised area where it looked like shaved material was pressed into the machined surface during manufacturing. before the install, this was covered by the zinc coating.

amazon accepted the return and I installed a 3rd rotor and it seems ok. won't really know for sure until everything is bedded in (akebono says 4-500 miles moderate driving for proper bed-in).

So... even the well-known name brands have their mistakes, too...

 

[Le_bow_ski]

Drilled and slotted rotors are often more susceptible to cracking that solids. I have drilled rotors on my Miata from the previous owner and most if not all of the drill holes have small cracks emanating from them. Interestingly, the cracks haven't enlarged in the past 60k miles I've driven with them but when it does come time to replace them it will be with solid rotors.

There's no real reason to install drilled or slotted rotors on a sanely driven street car, and while there may be reasons to have them on a race car they're also swapped out at very short intervals. The hot ticket for Spec Miata race cars is the cheapest solid rotors you can find with Napa no-name rotors being a favorite.

 

[Rolla07]

I have Akebono's and am very pleased. I bought jobber drilled and slotted which seem to be okay..stopping power could be better but i have drums in the back, which I think are the reason for that.

 

[tommygunn]

I thought Akebono said they don't require any break-in procedure for their pads. At least their ProACT pads, anyway.

Isn't the AT-300 slotted? That could cause some problems, right?

The Centric Premium rotors are said to be very good, and they cost half the price of the AT-300's. I have also heard good things about Fremax rotors.

Practically ALL brake rotors are made in China, except Fremax which comes from Brazil.

 

[Sequoiasoon]

Originally Posted By: meep
Just installed new front brakes on the tundra in my sig. Used raybestos at-300 rotors with machined slots, along with akebono pads. this combo has proved excellent in my wife's MDX, with a lot more braking power and headroom than before, absolutely amazing performance.

These rotors are pricey. Best you can find i ~$90 a corner up to $210 depending on where you look. They have a bit more thickness to the braking surfaces, with slightly less gap in between, or at least they appear that way in pictures.

The install was cake and this truck is 99% rust-free, so there were no surprises during the install.

Tremendous judder however, immediately after installing. I figured it was my error. took it all back apart and looked for trapped rust, poor rotor seating, and even took a sanding block to scuff them up. One of them had an arrow-straight hairline crack all the way across the braking surface on the front, and a dimple surrounded by raised area where it looked like shaved material was pressed into the machined surface during manufacturing. before the install, this was covered by the zinc coating.

amazon accepted the return and I installed a 3rd rotor and it seems ok. won't really know for sure until everything is bedded in (akebono says 4-500 miles moderate driving for proper bed-in).

So... even the well-known name brands have their mistakes, too...


Meep did you check SP part# to see if the slotted rotors fit?

I just did all 4 on the Sonata with the SP slotted and drilled. I got the Akebono Proacts front and rear from Pepboys. I had ordered Hawks HPS for front (and SP street plus) for rear. When I checked them out the SP's had EE temp rating printed on them vs Hawks FF (and Akebono). I didn't want mixed friction between the axles. I bedded them as I have done all my brakes with the 30-5 a couple stops and some 60-15 then a nice longer easy cruise to let them cool.

All I can say is that they are quiet and stops AWESOME as compared to before. I also went to firehouse a day later and 9 stops signs later there was no issues, felt just as good then as at first one. The Wagner Thermoquiets and factory rotors had SERIOUS fade by then a couple times where the car barely stopped once I got to firehouse. I like this setup now.

One thing to note from my experience whether it's the drilled or the "swept" slots as compared to the regular straight slots on the SP's I had prior. These are silent just like solid rotors even when I get on them hard like I did.

 

[meep]

Originally Posted By: tommygunn
I thought Akebono said they don't require any break-in procedure for their pads. At least their ProACT pads, anyway.

Isn't the AT-300 slotted? That could cause some problems, right?

The Centric Premium rotors are said to be very good, and they cost half the price of the AT-300's. I have also heard good things about Fremax rotors.

Practically ALL brake rotors are made in China, except Fremax which comes from Brazil.


correct-- akebono says 400 miles of moderate driving, that's all. yes, AT-300s are slotted--- they have been flawless on our other car, which is why i chose them again.


Originally Posted By: Sequoiasoon
Originally Posted By: meep
Just installed new front brakes on the tundra in my sig. Used raybestos at-300 rotors with machined slots, along with akebono pads. this combo has proved excellent in my wife's MDX, with a lot more braking power and headroom than before, absolutely amazing performance.

These rotors are pricey. Best you can find i ~$90 a corner up to $210 depending on where you look. They have a bit more thickness to the braking surfaces, with slightly less gap in between, or at least they appear that way in pictures.

The install was cake and this truck is 99% rust-free, so there were no surprises during the install.

Tremendous judder however, immediately after installing. I figured it was my error. took it all back apart and looked for trapped rust, poor rotor seating, and even took a sanding block to scuff them up. One of them had an arrow-straight hairline crack all the way across the braking surface on the front, and a dimple surrounded by raised area where it looked like shaved material was pressed into the machined surface during manufacturing. before the install, this was covered by the zinc coating.

amazon accepted the return and I installed a 3rd rotor and it seems ok. won't really know for sure until everything is bedded in (akebono says 4-500 miles moderate driving for proper bed-in).

So... even the well-known name brands have their mistakes, too...


Meep did you check SP part# to see if the slotted rotors fit?

I just did all 4 on the Sonata with the SP slotted and drilled. I got the Akebono Proacts front and rear from Pepboys. I had ordered Hawks HPS for front (and SP street plus) for rear. When I checked them out the SP's had EE temp rating printed on them vs Hawks FF (and Akebono). I didn't want mixed friction between the axles. I bedded them as I have done all my brakes with the 30-5 a couple stops and some 60-15 then a nice longer easy cruise to let them cool.

All I can say is that they are quiet and stops AWESOME as compared to before. I also went to firehouse a day later and 9 stops signs later there was no issues, felt just as good then as at first one. The Wagner Thermoquiets and factory rotors had SERIOUS fade by then a couple times where the car barely stopped once I got to firehouse. I like this setup now.

One thing to note from my experience whether it's the drilled or the "swept" slots as compared to the regular straight slots on the SP's I had prior. These are silent just like solid rotors even when I get on them hard like I did.


-- Checking on yours is my next step--- I wanted to run these through since I have some $ invested in them at this point.

***FOUND IT***: I drove in this morning and lightly rode the brakes to heat them up. There is a clear thermal pattern evident on the other rotor, the one that didn't have the crack. The pad is primarily contacting the very outside and very inside of the rotor surface, and isn't evenly pressing into the main area of the rotor face; face is caved in or concaved. I have arranged for a swap, and will likely never buy these again after they wear.

 

[Ken2]

I don't expect slotted rotors to have the cracking issues some drilled rotors have.

The stability of cast iron products, including brake rotors, depends on the manufacturing techniques. From another forum (and matches my experience): "Foundry technique is a factor in stability and hence in final accuracy

"Stability of iron depends mostly on slow, uniform cooling in the mold after casting. This in turn depends on molds of the proper design, and on allowing sufficient time for complete cooling before the casting is exposed to the air. There is possibly no other metal more stable than cast iron that meets the preceding two specifications [proper composition and cooling period]

"Despite its stability, cast iron does not differ from many other metals in that the removal of a substantial amount of material by machining, especially the outer skin, will alter its equilibrium

"The piece may or may not be free of stresses, depending upon the method by which it was machined.

"The theory that a cast iron part must be exposed to the weather to rust and "age" in order to stabilize it is a carry-over from the past. In the absence of closer measuring facilities or adequate temperature control, the stability of the iron was blamed. Supposed cases of instability might have been traced to machining practices, deflection or, most often, to temperature variations"
http://www.practicalmachinist.com/vb/woo...ability-261503/

I've used a dial indicator once to measure the runout and flatness of installed new brake rotors. I put new SP Performance brand rotors on my Tundra. They measured a max of 0.003" runout, and were very flat (I don't recall the measurement). On this truck 0.007" runout is allowable.

Slotted rotors allows the hot gases between the pad and rotor to bleed away to get more grip. Meep had been overloading his truck's front brakes, underloading the rears and the trailer brakes, and any way to beef up the fronts was important to him.

 

[Sequoiasoon]

Originally Posted By: meep

-- Checking on yours is my next step--- I wanted to run these through since I have some $ invested in them at this point.


According to the sp-performance website they are the same part # for my '03 Sequoia and your '06 Tundra.
SP rotor catalog

 

[surfstar]

I'm always confused by brake "upgrades" for street vehicles.

As long as your brakes are able to provide sufficient stopping power to lock up your tires / activate your ABS, how is anything an "upgrade"? We're talking street, stock, cars. Not running "hot laps" or anything.

 

[Greasymechtech]

Some of tow. Some of us commute in aggressive traffic. Some of us live in hilly areas. Some of us own vehicles with inadequate brakes. I don't live in a perfect world. I also don't use abs. I prefer a pad that responds to my foot pressure and doesnt fade when warmed up like all those quiet dustfree OE pads.

 

[Ken2]

Originally Posted By: surfstar
I'm always confused by brake "upgrades" for street vehicles.

As long as your brakes are able to provide sufficient stopping power to lock up your tires / activate your ABS, how is anything an "upgrade"? We're talking street, stock, cars. Not running "hot laps" or anything.

Meep changed things with his trailer and an outmoded manual trailer brake controller (since upgraded), and with air helper springs that took his rear brake proportioning valve out of calibration. This put an excess load on his front brakes.

 

[meep]

^^^yup^^^

and to be fair, I'm towing at 90% of the truck's rated capacity, in a vehicle that is known to have marginal brakes from the git-go. There's a whole other thread on that, and I've still got a lot of work to do, including a few suggestions to go ahead and check the trailer brakes for adjustment as well. I have injured wrists, so projects like this for me take a while--- I generally don't tackle it all in one day. I want to get the truck sorted out first, since it's also my DD. Brakes on this one have been an on-going issue since I bought it with over 100k on it and unknown history.

Not trying to get too off topic-- I was just trying to report that my experience with this product line has been shoddy this go-round, unlike the last time I purchased the AT-300s.

 

[zzyzzx]

Obligatory:

 

[dailydriver]

Originally Posted By: zzyzzx
Obligatory:

WHAT is that on??

 

[zzyzzx]

I have no idea. I would assume it's someone bored at a machine shop.

 

[meep]

dual wishbone setup by the looks of it... honda? look at the pink ring--- like a spacer to fit mismatched hub bores? shaved the caliper to either fit a larger rotor or a mal-sized wheel...

 

[ironman_gq]

Only time slotted or drilled rotors are really any advantage is if you use organic pads, ceramics and metallic don't gas out when they get hot. Their biggest selling point came from the high performance tuner crowd who marketed the [censored] out of them as the best thing ever. Truth is that on almost all street vehicles and even most race vehicles, a solid rotor is going to work better. They have less tendency to crack, have more material in them and a larger uninterrupted surface for the pads to work on. There could be some argument that drilled rotors cool better by allowing more air flow through the rotor but it is of minimal effect on a street vehicle that sees most of its time in non-braking situations. Having good brake fluid and the right friction material will make a much larger difference in your braking performance than slotted rotors will.

 

[SteveSRT8]

Great post!

Drilled are for bling, most rotors do not need to lose mass since they are effectively a heat sink. Cars shipped with drilled have excess braking capacity, generally very hi po. Slots are for pad issues when OEM.

And you are so correct on that last line. Folks have been confusing PAD issues with rotor issues for a long time!

 

[dailydriver]

Do the high end carbon-carbon braking systems offered on some VERY high performance models have drilled carbon rotors because of the crazy high heat levels these systems generate, even in some 'street' situations??

I understand that drilling carbon rotors is not as much of a drawback/no-no as on iron rotors since they are much less prone to stress risers, and therefore the subsequent cracking.

 

[artificialist]

Originally Posted By: meep
dual wishbone setup by the looks of it... honda? look at the pink ring--- like a spacer to fit mismatched hub bores? shaved the caliper to either fit a larger rotor or a mal-sized wheel...
That pink thing may be used with aftermarket wheels. The size of a hub on an aftermarket wheel isn't always the same as OE, so wheel manufacturers often supply a spacer so the wheel fits the hub.