Warped Rotors- Warrenty

Highly recommend downshifting, even with an auto. I'm at about 120K on my original rotors and I'm nearly hauling around the weight of another Tacoma on most of my long distance, over the mountains, trips.

 

At almost 4k mikes, used purchased my 2021 Taco. I complained to dealer while getting oli changed of a pulsation. They went for a drive and turned the rotors. however, when it's time for brakes, i'll go to my porsche indy who is shop foreman and have him take care of the brakes like it was his. We'll se what happens since he drives a taco too.

 

Its shake and bake, and I helped

 

it may be stupid rare for an individual who takes great care braking or depending on the vehicle but if you service vehicles for others you will see this on the reg. Shops all across this country keep their lathes humming every day of the week. TIR (total indicated runout) generally indicates rotor warp (think 99.99% of the time). The other 0.01% are machining defects and you’ll know when you install immediately. I haven’t jumped to any conclusions, I’m just explaining how this works because folks either don’t do this work themselves or don’t understand the physics or design of braking systems. Just so happened this was my emphasis in school and I have serviced brakes on passenger vehicles for the last 35 years.

 

I have 20 years experience. I don't see runout that continues front to back indicating warp anymore. When I started we used to see small rotors on 90s trucks do this, but its rare.

Most pulsations now are hot spots, pad material, or rust. All have run out, just not front to back, which would be a "warp".

 

Maybe 30 years ago. The majority of shops nowadays don't even have brake lathes. Never had out-of-spec rotors on the 4 vehicles I've worked on myself over the years. If you get vibration after install, it's more likely to be caused by rust or contaminants on the hub flange.

 

Just sharing some things I learned in some brake classes given by the manufacturer schools I attended in my years as a dealer tech.

What we consider warped rotors are rarely actually warped. Its almost always brake pad material that gets "stuck" to the rotor. This almost always happens when you have a very hot rotor and the brakes are applied while sitting still. For example you're doing 70 down the interstate, you take an exit and are using your brakes to slow down then at the end of the exit ramp you get stuck sitting at a light with your foot on the brake. The hot rotors get some brake pad material stuck to them.causing a "high spot" on both sides of the rotor. That thick part of the rotor is the pulse you feel in the brake pedal and steering wheel.

It sucks you're dealing with it but things like brakes are only warrantied fir 12mo/12k miles. I'd suggest either removing the rotors and having them cut or getting new, quality rotors.

 

^^^^^^
This!

 

Curious responses. After replacing rotors on my MDX (230k miles at the time), I became super sensitive to how I brake. Purchased my 2020 DCLB new. Drove it like a grandma. Took it in for service at just over 4k miles for bad vibration under braking. Dealer turned them. By 10k, at least as bad as before. Even my kid who drives a clapped Ford Ranger with 260k miles on it rags on my Taco's braking.

I'll not doubt the engineering types (above), but I'm a pretty consistent driver, I understand the issue with hard braking to stopped. I've experienced the same in a pair of rented 4Runners.

Now that I'm at 43k, I'll break down soon and purchase aftermarket rotors. I'd rather be disappointed in a good aftermarket rotor than disappointed in myself for buying OEM rotors.

 

I read about this too years ago in Popular Mechanics. They advised to not sit on the brakes much at all-let it creep a little to move the hot spot at the lights.

Been doing it ever since. The only rotors that have warped under my watch belonged to my ex-wife and gf.

I got over 110k on BMW rotors on a hard driven 335 coupe i owned. I slapped pads and 50k, 90k, and then sold the car.

About to slap pads on the rear of my 991 at 15k (soft pad+ hard driving).

Gf's Range Rover LWB is getting its 3rd set of rear pads next week at 58k miles, and changing rotors too (using cryo rotors). Front and rotors on this rig only made it 40k miles.

I drive the sporty vehicles hard and dont make an effort to baby brakes, but I dont speed up to stop lights and slow down hard and then rest on the brakes hot at a light. Guess who does that??

 

Mine had been warped for forever...just replaced the rotors and pads a few days ago. Hopefully these one last longer, lol.

 

Just about every woman i know, including my wife.

 

Nah. Never happened.

 

A couple of things I learned from Japanese driving classes to extend the life of brake components.

To prevent rotor warp, I try lessen the amount of time I sit on the brake pedal at a stop, usually by pulling my handbrakes at red lights. Which is actually a commonly taught thing in the UK&EU.

When the pads are sitting on the hot rotor, they would cool that area faster than the rest of rotor's surface, doesn't help that you are also applying braking pressure on that one spot. As that spot also cools, it can cause some material from the pad to stick to it, leaving high spots.

Things from continuous heat/cooling cycles like in city driving or coming to a full stop from an extended decent can accelerate it.

That absorbed heat would also go into the brake lines and boil the water which then introduces air into the system.

 

Toyota covers their brake drums in warranty when knowing they had an issue, but never heard them warranting rotors.

 

If memory serves Ford will warranty turning rotors for only the first 12,000 miles or one year. Its annoying cause you have to take 4 measurements of each rotor thats turned before and after and document them on the ticket.

 

The most common cause of pulsation is called thickness variation. Thickness variation is caused by environmental and pad composition. If you're having reoccurring issues I suggest ditching the ceramic pads for a semi-metallic composition. Ceramic pads do not scrape the rotors clean like metallic pads. Basically, any flash rust (wash your car and look at the rotors after, they rust almost instantly) is actually "burnished" into the rotor with ceramic pads. Where the pad was sitting (during the rusting) doesn't rust so you wind up with a low spot there. After repeated flash rusting events the rotor is not "parallel" in thickness.
Semi metallic pads will scrape more of the rust off on the first pass.
I stopped using ceramics because of this, and because of pad transfer to the rotor. Save some money and get metallic pads, they're cheaper and stop better at a wider range of temps they even last longer. It's all I buy now and I'll NEVER go back to a ceramic pad after seeing how much better metallic's work.

 

I tried metallic pads on my tundra, and didn't like them. They were noisy, and never stopped as well as the ceramic ones until you got enough heat in them. I got over 80k miles out of a set of ceramic pads, and ebc rotors on my tundra.

 

That's completely opposite of what pad manufacture information says. They recommend metallic based pads in cold climates because they stop more consistently in a wide range of temps, especially cold weather. If they didn't stop as well they were not true metallic pads. This is why many european cars come with semi metallic. As far as noise and dust, I personally don't give a shit. I want the best stopping pads I can get.
You should use what you get good results from, but my point was a metallic pad will clean off rust and pad transfer much better than a ceramic. So in some climates you'll get good results with ceramics, some you won't with regards to pulsation.

https://www.repairsmith.com/blog/ceramic-vs-semi-metallic-brake-pads/

 

When installing new rotors....get a dial indicator in them and make sure that runout is under control...you want to see less than .001" of lateral runout. Anything over about .003" will turn into a pulsation in 5-10K miles.

Dirty hubs, bent hubs, bad rotors can all result in excessive runout. Also, torque the wheels properly.