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Tundra front Rotors


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#11 fuzzymarindave

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Posted 10 May 2021 - 05:41 AM

I think that the safe choice for most makes and models would be OEM rotors from the dealer.  For myself it has been a long time since I replaced any rotor.  On my last four brake jobs (four different vehicles) I’ve only swapped in new pads as the rotor thickness was within spec. 


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#12 Vic Harder

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Posted 11 May 2021 - 09:03 PM

Great description!


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#13 EM4

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Posted 12 May 2021 - 03:59 PM

We have an 05 Tundra with an ATC Ocelot on full time - bought the truck with 80K on it, now have 187K (over eight years). Replaced the front rotors at 100K and they are still in good shape (OEM). Drive over Teton Pass fairly often so they get used. But I drive carefully and am not subject to city driving much. Maybe that is the difference if you drive in heavy traffic for the most part.

Thanks Buffalo, maybe I am hard on brakes. But I think OEM is the way to go.


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#14 EM4

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Posted 12 May 2021 - 04:02 PM

I had an 04 Tundra and ran the original brakes and rotors up 105,000 miles before replacing the pads and just had the rotors turned. The Hawk I had at the time was only on 25% of the time. My '15 Tundra had 36,000 miles on it and I never noticed any warping. I live in the Sierra foothills where most of the roads are twisty turny.

Thanks Ronin. I had thought of just turning the Rotors but was under the impression that for the difference in cost going with new ones is/was the way.


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#15 EM4

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Posted 12 May 2021 - 04:05 PM

No warping issues with our 06 Tundra / Hawk combo, at 135k with ten years carrying the camper 75% of the time.

However, emergency stop capability has always been much slower than I want.

I think the weight of the 07 is a tad more, but emergency braking with mine is no issue what so ever. Thx for your input.


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#16 EM4

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Posted 12 May 2021 - 04:16 PM

Rotors do not warp - that's a myth that even many of the most experienced mechanics continue to push since they really do not understand what is taking place. Ever wonder why turning "warped rotors" never really helps and the issue comes back again and again? It's because on a molecular level the brake rotors have changed due to improper use. Let me back up a few steps and begin by talking about how to bed brakes in.

 

When new brake pads and rotors are initially used they are not familiar with one another - there's an exchange that must take place prior to them becoming most effective. Again, this occurs on a molecular level and largely involves depositing a layer of the brake pad onto the surface of the rotor. This may sound strange but bear with me. In order for the braking system to work properly a uniform layer of the brake pad must be bonded to the rotor. Each brake pad manufacturer normally is able to provide a guide on how to bed (introduce) their brake pads. This normally involves repeated stops in quick succession from 60-5 MPH. Depending on the pad it may take five to ten stops. Now this is the most critical part...

 

You can not come to a full stop during the bedding nor can you stop after bedding the pads until the rotors cool down. This is either sink or swim folks - you either have a happy relationship between the new pads and rotors or if you have stopped you have began to create inclusions...that's fancy word for problems in the cast iron brake disc.

 

Remember above I stated that this new molecular friendship must be uniform? If that pad material is transferred properly at elevated temperatures and the system is permitted to cool at a uniform rate then all is well. If you come to a complete stop while bedding the pads or before the rotors cool down guess what happens? The majority of the rotor is now exposed to ambient air while a certain section remains insulated under the brake pads. This hot spot leaves us with a non-uniform deposit. Now we are beginning to head in the wrong direction. At this point you may begin to feel the slightest of shudder or pulsation with your brakes simply because there is a non-uniform deposition of brake material on the surface of the rotor. Some argue that rotors can be saved at this point but I have never seen this being successfully accomplished.

 

Now that the rotor has a non-uniform deposit of brake material the braking system begins to operate differently. As the pad reaches this area slightly more friction and heat is created and this problem begins to compound itself. Very quickly the problem goes beyond a non-uniform deposition of brake pad material and the cast iron rotor itself begins to change in that area to a cementite phase. This phase is a description of the microstructure of the gray cast iron rotor. I am working from memory but it is suffice to say that the change in phase in this one area is now really taking us into what can be described as a downward spiral. This new microstructure in one area is hard with a high level of friction so guess what happens when brake pads attempt to do their work? That area becomes hotter and the cementite phase grows and begins to penetrate deeper into the rotor. And this is why turning rotors is only a temporary solution - the microstructure of the rotor itself had changed in one area.

 

Of course, when we purchase a new vehicle we drive it very carefully and are light on acceleration, turning, braking, etc. This is good but it never really fully introduces the brake pad and rotor to each other in a proper way through bedding. But after some time, when you are working your truck like a mule, dragging heavy loads up and down hills, maybe bringing the brakes up to elevated temperatures, etc. And stopping while waiting for a light shortly after really heating the brakes up...the seeds are planted and the downward spiral begins.

 

We could go one into much greater detail but I would encourage each of you to read up on brakes and learn more. The truth is out there although you must wade through much unintentional misinformation to find it. Me, I raced for years and my life depended on brakes so I am quick to find manufacturers information regarding the bedding of their brake pads, or I have done it so much I know when I smell the outgassing and begin to feel the brakes lose effectiveness that just another cycle or two then I can drive without stopping and permit everything to cool down.

 

And just remember, never come to a complete stop with very hot rotors. If you promote uniform deposition of brake pad material and gradual cooling of your gray cast iron rotors your brake system will love you.

Many thx Chet, Yes a lot more reading into this is needed. Cheers


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#17 fuzzymarindave

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Posted 03 July 2021 - 06:30 PM

One way to check for possible warping is a dial indicator.  Useful for many other applications too.  Lots of inexpensive options for example:         https://www.amazon.c...2xpY2s9dHJ1ZQ==


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