3rd gen brake rotors not serviceable?

I took my rotors in to have them turned this past weekend and two different auto parts stores told me the '16 Tacoma rotors can not be turned. I was forced to purchase new rotors instead. Is this common knowledge?

 

I'd ask a dealer.

 

Parts stores don't like cutting rotors anymore.

I've cut probably 500 tacomas rotors in my career.

I use the on-car-lathe for all Tundras and only some Tacomas. For the most part I'll use a stand lathe on a Tacoma rotor if it's good condition.

I don't like cutting the drums, but that's usually due to equipment and the nature of how the Toyota drums are mounted.

 

Were you able to push the pistons back in the calipers? I only ask because a while back I read a thread about posibly having to hook up some kind of obd2 device to relieve the pressure off of the system and without it you would not be able to push the pistons back. I don't remember it ever being confirmed.

 

Modern cars generally don't have a huge amount of extra material on their brake rotors, so while they're machinable it's often not worth it because there's not enough meat there to be worth machining.

Why do you think you need your rotors turned anyway?

 

I don't turn my rotors unless my brake pedal pulsates when braking.
Yes, it's recommended to turn them every time at the shop to avoid a comeback 3 months later and charge a little extra, but if you DIY its worth the risk imo, I just replace the pads again and turn them or buy new ones.

And I don't like rotors that can't be turned as I usually turn all new rotors before installing because they may get out of round during shipping & handling or stacked up high on top each other for storage.

 

You have a very strange idea of how cast iron works.

 

Why I like full cast vs composite.

 

??

 

I've never put new pads on unturned rotors and been happy. Something about the glazed smooth rotor on new pads I can't deal with. The satin finish of freshly turned rotors on new pads never squeak or chatter.

 

Which is exactly why you are either supposed to turn the rotors or replace them. If you just do a pad slap, there is a layer of glaze from the old rotors and pads that have embedded into one another. New rotors and pads are slightly rough so that they can both break in together and create a layer of adhesion.

 

if this is true I am guessing the rotors are lighter and thinner than the previous ones, for the mpg GAINZ

 

Among other things, cast iron doesn't "warp." So the idea of it getting all bent out of shape from sitting stacked in a warehouse like a vinyl record is... not correct.

 

If you're using the same pad compound it's fine, you just have to bed them properly. Changing pad compounds on the same rotors without turning them first makes it like trying to brake with a squeegee on glass.

Back when I had enough spare time to actually race fairly often, I used to pre-bed six or seven sets of brake pads onto two sets of rotors over the course of a day, and then I'd be set for the whole season.

 

As somebody who works in a facility that manufactures/repairs cast iron valve bodies (refinery size), cast iron certainly does warp and bend. It won't go very far before it breaks, but it does.

 

The way brakes are used in racing differs wildly to how I drive to get a burrito. I mean, I don't ride the pedal and I don't accelerate at WOT then brake hard 1 second later. I think the typical driver would notice much more going on in the form of squealing and chattering than racing would produce.

Isn't the generally accepted practice to turn rotors when replacing pads or was every machinist from 1950 to 1990 wrong?

 

never done so on any vehicle.
Always found doing so has the brakes be a bit noisy. I always replace rotors and pads together.

That and I just think now days with labour cost always being so much its cheaper to just replace than it is to pay someone to machine them.

 

yes turning rotors to remove old grooves so new pads match up perfectly is how it's done. that, or new rotors.

just installing new pads w/o removing caliper is OK too, but you do not get max braking performance that way,
and while the new pads are trying to match the old grooves, over time, it may never achieve max brake performance
and might make the grooves just much worse, because more grit can get in there while the pad is flat but the
rotor has grooves. that means more dirt can work it's way in. it's the hobo method, and cheap...and a loss of performance

 

Most of those would be nodular ("ductile") iron, I should think? I certainly test enough nodular iron valves. Grey iron, like a brake rotor, has "some" ductility but in practical terms its not even measurable.

 

Cheap cast iron tends to have hard spots, which will cause them to wear unevenly.

I don't know for sure, but non serviceable rotors could be made from higher quality meehanite to significantly reduce the chances of that happening.