Rotors at 23k miles?

[Deadman]

Normally I agree with everything deadman says, but in this case, I kind of don't. Unfortunately so many vehicles have crappy brakes that dob okay in stop and go and city driving, but not mtn passes like here in Co. Especially domestic vehicles. On my last jeep, about the third mountain trip (where it had nothing to do with stopping and holding the pads in one place as it was about a 15 Mike descent with another 30 mi of highway afterwards) they were warped. They are crap and can't handle the heat. I put on a full set of power stop slotted and cross drilled rotors, and put about 80k miles on the rotors, changing pads twice.

I was hoping these large rotors might do better but this doesn't give me much confidence.

And yes, for about 20 yrs I've been conciously slowing like this as I used to race rice burners. Had to do that a lot during road courses.

My sister had a f150 and she warped the rotors on it after pulling her horse trailer every few thousand miles. I told her how to cool and brakes and she never warped another set after that....... I'm not saying these rotors are good or bad quality, but either way cooling them will reduce the warping. You can't superheat metal and then cool it at different rates and expect it to not warp eventually.

 

[5280tunage]

Couldnt agree more. But I also think that for say an extra $100 worth of cost when building these 80k vehicles, they could put some vented (or slotted/drilled) rotors that would not only last better, but reduce fade etc. But then again, why would they, it might reduce their service revenue since most people would just go to the dealer and pay for new ones when they tremble.

Heck, offer us an option, you know, like how porche often has between 2 and 4 brake options for every vehicle.

 

[Deadman]

Couldnt agree more. But I also think that for say an extra $100 worth of coat when building these 80k vehicles, they could put some vented (or slotted/drilled) rotors that would not only last better, but reduce fade etc. But then again, why would they, it might reduce their service revenue since most people would just go to the dealer and pay for new ones when they tremble.

Heck, offer us an option, you know, like how portion often has between 2 and 4 brake options for every vehicle.

Ya know, up until I swapped the sway bars on my Expedition I always thought the factory brakes were adequate. BUT, now after swapping the sway bars, I am able to drive it so much more aggressively that I notice the poor braking ALL the time. I'm not about to mess with it, but the factory brakes aren't anything super impressive to me, so I'm sure they aren't of high quality as well.

 

[Rossue]

Do 4th Gen Expeditions have phenolic brake caliper pistons? If so they can hang up and not fully retract after braking to cause rotor warp.

 

[Dice Roll]

Factory rotors are often garbage. I drive ahead and plan my stops. Some stuff is just junk. Same driving after good quality parts go on will tell you if it’s you or the factory garbage. I’ve never had a quality set warp after taking off factory garbage.

 

[haviland]

The rears failed on my new '17 Expy after maybe 24k miles. Couldn't believe they were NOT under warranty at that time. Other brakes on 3 earlier Expys (60- 70k miles) were never replaced.

The rotors didn't appear to be warped, but the pads wore unevenly. I replaced pads and rotors myself with decent quality components for around $500.

 

[EngRWW33]

It's kinda funny & classic auto stories. Some people (companies) say rotors warp and others say they don't. I think a lot more say they don't than do, taking into account the source. I dunno ... I only know what I read since I've never put a runout gauge on one and been there during casting and run testing over various conditions. My limited knowledge of metallurgy tells me there are probably some defective castings out there that will probably deform once they go through extreme heat cooling cycles. But thats the exception not something that happens to all rotors. I have read that if you brake incredibly hard and your rotors turn red with heat, they are about 400 degrees which is nowhere near melting temperature of cast iron which is 1200 degrees. Cast iron doesn't even soften at 400 degrees, it's just hot. Very credible sources say that what people think is warping is actually brake pad material unevenly deposited on the rotor. If you break in or set your new pads properly that helps avoid that situation ... they say. You know ... THEM, they say that. Also, seems to be generally agreed not to heat your rotors up and then stop and apply brakes and hold the pads against the red hot rotor. That will fuse a load of pad in that spot then they will pulse, which is sort is sort of in common with the warping camp people's advice. As I said - I dunno.

What about if you have quality properly manufactured rotors ... heat them up with extreme braking and then run through a large puddle. If the "cooling theory" held water then all rotors would warp would they not? Of course this happens all the time so and I don't hear a lot of people telling that story on a regular basis. I'm sure some people claim that, but look long enough and you will find someone who claims anything. Like me!

There is other stuff like how they were installed and such.

https://www.mechanic.com.au/news/solved-the-mystery-of-warped-brake-rotors

https://www.brakeandfrontend.com/brake-rotors-dont-warp-the-earth-is-not-flat/

I'm surprised this was skipped over and not talked about more. 99.99% of the time, its not "warped rotors" (i.e. metal which has heated to the point of losing it's original shape/form) but rather uneven pad material deposits. When this happens, you can usually have the rotors turned (shave a bit off) and re-bed the brakes, or just go through the brake bedding procedure (Google) to evenly distribute pad material again.

If you drag the breaks down a long decline and then sit at a stop light without letting the rotors cool properly, pad material will adhere (melt) itself onto the rotor at that specific spot which can cause the pulsing.

Either way don't spend that kind of $$$. Some Centric blanks and pads should run you less than $300 on RockAuto/Amazon. Take these to a local mechanic if you can't do them yourself and you should get the normal install time which should be 4-5 hours for all 4 corners. Still 1/2 of what you were quoted.

 

[Plati]

I'm surprised this was skipped over and not talked about more. 99.99% of the time, its not "warped rotors" (i.e. metal which has heated to the point of losing it's original shape/form) but rather uneven pad material deposits. When this happens, you can usually have the rotors turned (shave a bit off) and re-bed the brakes, or just go through the brake bedding procedure (Google) to evenly distribute pad material again.

If you drag the breaks down a long decline and then sit at a stop light without letting the rotors cool properly, pad material will adhere (melt) itself onto the rotor at that specific spot which can cause the pulsing.

Either way don't spend that kind of $$$. Some Centric blanks and pads should run you less than $300 on RockAuto/Amazon. Take these to a local mechanic if you can't do them yourself and you should get the normal install time which should be 4-5 hours for all 4 corners. Still 1/2 of what you were quoted.

I'm biting my tongue ...

Worth repeating (MrEng's advice)-->There are those that say you can even correct pulsing brakes by executing the "bedding in" process IF the root cause of pulsing is uneven brake pad material deposition on the rotor.
It can work in some cases I've been told. Not a guarantee.

In reality there are multiple root causes for pulsing brakes and brake pad deposition is only one. I'm sure MrTrain would agree that some rotors (manufactured in China) were not cast/heat treated/ground properly and might deform later on the vehicle. Improper installation is another root cause I guess. I dunno.

I'm like Sargent Shultz .... I know NOTHING, I know NOTH_ING.

 

[Fozzy]

I would think if you “ warped “ your rotors. You would know you did something wrong. The smell of burning brake pads is really strong. The reduced stopping distance should be pretty obvious. If it was that easy you would see glowing rotors at night at all the stop lights or coming down long grades.


Sent from my iPhone using Tapatalk

 

[Motorcity muscle]

It's kinda funny & classic auto stories. Some people (companies) say rotors warp and others say they don't. I think a lot more say they don't than do, taking into account the source. I dunno ... I only know what I read since I've never put a runout gauge on one and been there during casting and run testing over various conditions. My limited knowledge of metallurgy tells me there are probably some defective castings out there that will probably deform once they go through extreme heat cooling cycles. But thats the exception not something that happens to all rotors. I have read that if you brake incredibly hard and your rotors turn red with heat, they are about 400 degrees which is nowhere near melting temperature of cast iron which is 1200 degrees. Cast iron doesn't even soften at 400 degrees, it's just hot. Very credible sources say that what people think is warping is actually brake pad material unevenly deposited on the rotor. If you break in or set your new pads properly that helps avoid that situation ... they say. You know ... THEM, they say that. Also, seems to be generally agreed not to heat your rotors up and then stop and apply brakes and hold the pads against the red hot rotor. That will fuse a load of pad in that spot then they will pulse, which is sort is sort of in common with the warping camp people's advice. As I said - I dunno.

What about if you have quality properly manufactured rotors ... heat them up with extreme braking and then run through a large puddle. If the "cooling theory" held water then all rotors would warp would they not? Of course this happens all the time so and I don't hear a lot of people telling that story on a regular basis. I'm sure some people claim that, but look long enough and you will find someone who claims anything. Like me!

There is other stuff like how they were installed and such.

https://www.mechanic.com.au/news/solved-the-mystery-of-warped-brake-rotors

https://www.brakeandfrontend.com/brake-rotors-dont-warp-the-earth-is-not-flat/

Two good articles here, thanks for posting.