[Mikecol]

I have been told by dealerships and repair shops that they will only replace pads with new rotors, and/or sometimes only after turning the rotors. In this day and age of everyone getting sued for every little thing people can think of, changing the rotors with the pads is the most fool proof conservative way to do a brake job. But I do think it is overkill.

I do my own repair work and I usually just change the pads if the rotors are still good (not warped and pulsating). If the rotors are pulsating, I would be OK with turning them once as long as they are still in spec after the turn. They only take a couple thousands off the rotor when they turn them so it's not like they are removing half the thickness. But they do tend to warp after you have them turned, even with the small amount taken off.

I have also found that if you go to a local parts store (like an O'Reilys Auto Parts) and get their lifetime warranty rotors that they have been very good and sometimes are not much difference in cost than having the rotors turned, or close enough that it makes sense to just put new ones on.

I have brake jobs where I changed rotors to new, or just turned the rotors, and I've done just a pad change and left the rotors as is. No matter which way I do the repair, I still get full braking power. I just do a couple fast stops from about 45 mph to get the pads seated well, and they seem to work fine. Again, to be clear, I do think turning the rotors or replacing them results in a better brake job, but I think the difference is negligible for all practical purposes.

I have found the Wagner Thermoquiet pads are excellent. No brake dust, they stop well, no noises or problems, and last very well. Lifetime warranty also.

One last caution. I have in the past changed only the pads that needed to be changed (such as just the front, or just the rear), but I don't recommend that. If the pads you get have more or less friction than the pads installed, you will shift the braking force (and thus the heat) to the pads that grip the best. And that results in that set of rotors or drums getting hotter than they should.

Also, it changes the braking force balance of the car/truck, so it could make the rear brakes lock up before the front brakes and cause an accident. Or it might shift the braking force more to the front resulting in front wheel lock up with less braking force from the rear, resulting in longer braking distances.

So, when you do a brake job, do the front and back at the same time with the same brand of pads.

 

[eharri3]

On my last truck, 04 Dakota, the brakes were crap. Had a shudder at like 8000 miles. I had them turn the rotors. I had the shudder again at like 35K. Replaced pads and rotors, all aftermarket, did not have to touch the brakes again before selling it 50K later.

On my Tundra I started to get a wobble at 35 or 40k. Replaced pads, turned the rotors. Needed brake work again 60K as pads were fairly low. This time around I did both pads and rotors. I am now at 90K. It drives perfectly and they just told me I'm not even close to half shelf life on anything yet.

It is a combination of the factory rotor materials on newer vehicles not dissipating heat that well, which is exacerbated on heavier vehicles, and me being hard on brakes. The lesson I have learned is that it's a penny wise/pound foolish scenario. I can cheap out and turn the rotors on that first brake job, but I'll probably have to be under there for brake work again in a couple years. If I spend more money and replace everything on that first brake job, I usually don't have to do anything for at least 50K which is 5 years for me. At which point I can get away with a rotor turning and be good for another few years.

No, you don't HAVE to replace rotors every time you get a brake job. But it can be more cost effective over the life of the car if you at least do it the first time, if you normally pay someone for that stuff.

 

[Mikecol]

Brake rotor warping is a issue with how hot the rotors get, and how they cool off. Thicker rotors resist heat better than thin rotors (it takes more heat to raise the temperature of a thick rotor vs a thin rotor). The amount of heat generated is directly proportional to the how hard you are pushing on the brakes, how fast you are going when you apply the brakes, and the length of time you hold down on the brakes, and the weight you are stopping. The faster you stop, the more heat that is generated. The higher the speed from which you stop, the more heat that is generated. The heavier the vehicle (and trailer), the more heat that is generated.

The issue is that high speed stops generate a tremendous amount of heat. And high speed fast stops generate exponentially more heat than a high speed stop. And high speed fast stops with a loaded vehicle generates exponentially even more heat.

The issue that causes the brake to warp is how the heat is dissapated. Extremely high heat will just plain warp a rotor. If you hold the brakes on for a long time, like going down a hill, you can warp to rotors.

But usually what happens that you do a high speed stop like coming off an exit ramp from the highway, generate a ton of heat, then stop at a stop light at the end of the ramp and sit there for a couple minutes. This allows the part of the rotor that is exposed to air to cool, but the part of the rotor that is covered by the brake pads stay hot, and the rotors warp.

To prevent warping, pay attention to the type of stops that generate high heat. Don't stop fast when you don't have to. And when you do have to stop, instead of doing a full stop, stop just a little short and let the truck slightly roll to allow the rotors to cool evenly. Especially when you do a high speed stop off the highway. It does not have to roll much, just a very slight roll as you wait for the light or traffic.

This little trick will make a huge difference in how long your rotors will last before they warp. I am in sales, with lots of highway miles and lots of high speed stops. Doing the slow roll thing, I have not warped a rotor since 2002. It really works.

 

[ratherbeflying]

I tend to change rotors with pads although there were times money was tight and I would do just the pads if the rotors looked ok and there was no pulsing. I've never put a dial indicator on them but probably wouldn't be a bad practice if you wanted to do just pads. Personally I think the Tundra brakes are shit to begin with even after the 2005 model year.

As far as chain repair shops the ones around here get the cheapest stuff they can get from the local chain auto parts stores. AutoZone and Advance Auto are generally their go-to if it's not a dealer only part.

 

[24hrsparkey]

I do not understand why turning the oem rotor just a lil bit to true it up , will make it warp again easily .
Yes if you take it way far to the minimum thickness , its allot less heat soak mass and bad stuff may happen .

BUT enough people on the forum have tried to true up these rotors with VERY poor results , so must be true !

 

[mrmachinist]

I do not understand why turning the oem rotor just a lil bit to true it up , will make it warp again easily .
Yes if you take it way far to the minimum thickness , its allot less heat soak mass and bad stuff may happen .

BUT enough people on the forum have tried to true up these rotors with VERY poor results , so must be true !

What people don’t understand about metal is that it has stress in it. When metal goes through heat cycles, the stress changes. It can cause more stress, less stress, or cause the stress to be uneven across the part. The uneven stress is what will normally cause rotors to warp. I deal with metal bending and warping every day at work.

For instance I am running some 10” OD parts 42” long right now. Before they were heat treated they were straight within .005”. Now after going to heat treat, it’s about .150” runout. Granted that was 3 separate heating sequences up to 1600 degrees.


Sent from my iPhone using Tapatalk

 

[Tedrick123]

I have a 2010 with front rotor warpage issues as well. They've been replaced, then turned once, and warped after 10k again. I'm ready for after-market, but could use some recommendations on both rotors and pads. Thanks in advance!

 

[IamRay]

Powerstop from Rock Auto. I've used them on other vehicles and now that I have almost 75K miles on my 2015, I'll go with Powerstop Heavy Duty rotors and pads when it's time.

 

[Calson]

At 28,000 miles I had to replace the pads on a Chevy truck and was told the rotors were so badly warped that they would need to be replaced as well. I found aftermarket rotors and calipers that cost roughly the same as only the GM rotors would have cost and so replaced all the GM parts. That truck's brakes required no more attention for the next 150,000 miles and were OK when I sold it. Our 2007 Prius with 98,000 miles of driving still has 90% of the pads remaining and we will be selling it before it will need its first brake job.

If I had premature failure of an OEM part I would look for aftermarket parts of higher quality to use instead. Labor cost is the same either way and independent garages have never refused to use the parts I have brought in for any repair job on any vehicle.

Some pads are promoted as having a much longer life and that means they use a harder material which is going to accelerate wear of the rotors. I would rather replace the pads more often and minimize wear of the rotors. Warping may be from abuse by the driver or it is often the result of the manufacturer undersizing the brakes for the vehicle. This undersizing is why the stopping differences and brake fade is so varied among similar vehicles. I care more about the stopping distance than the 0-60 mph times for a vehicle when choosing what to buy.