Recurring brake rotor problem

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newbie003
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Recurring brake rotor problem

Post by newbie003 » Mon Mar 26, 2018 2:47 pm

I've been having an issue with our 2014 Buick Enclave, where last year we had to have the brake rotors ground(?) as they were causing a grinding sensation when braking.  A year later it's doing it again.

Buick says they'll fix the rotors for free again (still under warranty) but they now say I need new brakes as well (I guess new brake pads, I'm not certain, I have to call them back).

So, 2 questions:

1.  What might the underlying reason be why the rotors keep needing to be ground down?  After this year it's out of warranty and I'm worried this will happen again next year.

2.  Is it likely (or at least plausible) that I need to new brakes due to the bad rotors?  I want to fight for them to pay for the brakes as well, if I can claim that the bad rotors caused the brakes to wear too quickly.

Thanks for any thoughts!

barnaclebob
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Re: Recurring brake rotor problem

Post by barnaclebob » Mon Mar 26, 2018 2:50 pm

The brakes on my altima make a grinding/groaning noise under hard braking but both the pads and rotors look fine and performance is good so I've just lived with it. Its not an earsplitting or cringe inducing kind of noise. Coming up on 90k miles for the OEM pads and they'll need to be changed soon anyway. Maybe that will fix it.

Do your rotors look normal?

Is it a grinding sensation or a pulsing sensation?
Last edited by barnaclebob on Mon Mar 26, 2018 2:52 pm, edited 1 time in total.

onourway
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Re: Recurring brake rotor problem

Post by onourway » Mon Mar 26, 2018 2:52 pm

This is almost certainly a build-up of corrosion on the rotors.

Where is the car stored when not driven? Does it sit for periods of several days to a week or more without being driven?

You may need new rotors and pads when this happens. You will not need new brake calipers.

newbie003
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Re: Recurring brake rotor problem

Post by newbie003 » Mon Mar 26, 2018 2:53 pm

Car sits outside. Is driven every day. I've never experienced anything like this with prior vehicles :(

onourway
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Re: Recurring brake rotor problem

Post by onourway » Mon Mar 26, 2018 2:59 pm

newbie003 wrote:
Mon Mar 26, 2018 2:53 pm
Car sits outside. Is driven every day. I've never experienced anything like this with prior vehicles :(
Outside on grass, stone, asphalt?

What is the weather in your area? Wet or dry?

Maybe it's not corrosion, but this is by far the most common source when people complain of grinding brakes in my experience.

What did the mechanic say when they ground them last year? What was causing them to need it? It should have been readily apparent upon inspection. Corrosion is easily visible. If it was damage due to malfunction that would look distinctly different and also been obvious. Also, many modern brake rotors do not have ample material to allow them to be safely ground down. Perhaps they should have been replaced instead.

Brakes are incredibly simple and 99% the same among all vehicles so it should be fairly trivial to determine what the issue is. If it turns out to be a design fault that may be harder to deal with - but any competent mechanic should determine if that's the source fairly easily.

neilpilot
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Re: Recurring brake rotor problem

Post by neilpilot » Mon Mar 26, 2018 3:00 pm

newbie003 wrote:
Mon Mar 26, 2018 2:47 pm
  Is it likely (or at least plausible) that I need to new brakes due to the bad rotors?  I want to fight for them to pay for the brakes as well, if I can claim that the bad rotors caused the brakes to wear too quickly.

Thanks for any thoughts!
It's possible that you may need new rotors due to bad brakes, not the other way around. Specifically, if the pads are too close to the rotor (not retracting) when not braking they could possibly result in excessive noise and wear if the pads are rubbing against the rotor. There are 3 things I can think of that could cause this:
[1] a stuck or sticking pistons in one or more of your brake calipers, typically due to dirt and/or rust on the caliper piston, [2] missing or improperly installed anti-rattle springs or retaining clips, or [3] poor design

bloom2708
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Re: Recurring brake rotor problem

Post by bloom2708 » Mon Mar 26, 2018 3:04 pm

The brake rotors could be slightly undersized for the weight of the vehicle.

Heat caused by hard braking can warp rotors. That causes the pulsating. Rotors can only be "turned" (smoothed out) a few times before they get too thin.

Many variances here. If these are the original rotors, they might just be too thin to turn again. If replacement, they could have been cheaper. Neilpilot also makes some good statements.

Pads are made of different materials and usually matched to rotors that are smooth or slotted. Original Equipment rotors are usually more expensive and some choose cheaper routes.

Some cars just have tendency to warp. Hard stop/go driving and the style of braking can cause issues. Some just brake much harder. People are constantly roaring by me to get to that red light ahead just a few second before me.

If there is an Enclave Owner's forum you might search and ask for recommended rotor/brake pad sets that people have had luck with.
"We are here not to please but to provoke thoughtfulness" Unknown Boglehead

newbie003
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Re: Recurring brake rotor problem

Post by newbie003 » Mon Mar 26, 2018 3:13 pm

Thanks everybody. they didn't have much info (that they'd tell me anyway) in their notes from last time.

I'll go ahead and replace the pads (my cost) while they do the rotors (under warranty).

I made sure to have them tell the manager (for whatever that will do) that I want it to be well documented that if this happens again a year from now, they need to consider it part of a warranty issue as it happened twice under warranty. I know, not going to do much but whatever...

Hopefully between new pads and new rotors I'll be good to go. If not, I'll bring it elsewhere first for diagnosis, then back to Buick to see what they'll do for me.

telecaster
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Re: Recurring brake rotor problem

Post by telecaster » Mon Mar 26, 2018 3:14 pm

Severe over tightening of the lug nuts can cause this over time.

Those lug nuts should be tightened to a manufacturer specified range of ft lbs. Many mechanics put an impact gun on them and crank the snot out of them. Sometimes this can be 1.5x, 2x or more of the requirements. I've seen professional places do this on several occasions :(

njdealguy
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Re: Recurring brake rotor problem

Post by njdealguy » Mon Mar 26, 2018 3:19 pm

Just a suggestion but if it comes down to having to pay to have new brake pads and rotors (and do not know how to do by self), what I did a month ago on my 2012 Honda Accord was buy them from the Auto parts store (front and rear wagner thermoquiet ceramic brake pads and high quality rotors), and found a mechanic on craigslist who works for a dealer and does mobile car maintenence for some side income who did the work in my driveway (took him 2 hours) for 70 dollars. In total, cost me about $275 in total ($205 for the parts and $70 for labor). Doing it at a dealer or other shops would have easily cost 2 to 3 times of this total.

ZapRowsdower
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Re: Recurring brake rotor problem

Post by ZapRowsdower » Mon Mar 26, 2018 3:33 pm

telecaster wrote:
Mon Mar 26, 2018 3:14 pm
Severe over tightening of the lug nuts can cause this over time.

Those lug nuts should be tightened to a manufacturer specified range of ft lbs. Many mechanics put an impact gun on them and crank the snot out of them. Sometimes this can be 1.5x, 2x or more of the requirements. I've seen professional places do this on several occasions :(
+1, almost every time I have work done at a shop I have to adjust the lug nuts, usually after getting out my biggest breaker bar to loosen them.

wrongfunds
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Re: Recurring brake rotor problem

Post by wrongfunds » Mon Mar 26, 2018 3:44 pm

Once you cut the rotors, you make it easier for them to wrap again. It is just the physics. Never let dealer cut the rotors, especially under warranty. Insists on getting new rotors instead.

alfaspider
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Re: Recurring brake rotor problem

Post by alfaspider » Mon Mar 26, 2018 3:53 pm

bloom2708 wrote:
Mon Mar 26, 2018 3:04 pm


Heat caused by hard braking can warp rotors. That causes the pulsating. Rotors can only be "turned" (smoothed out) a few times before they get too thin.
This is actually a myth. Your brake fluid will boil off and/or pads will melt into a puddle long before the rotors would ever get hot enough to physically warp. I have boiled high-temp racing brake fluid on the track without warping rotors. Some reading by a leading brake manufacturer:

http://www.stoptech.com/technical-suppo ... ther-myths

What people call "warped" rotors is actually caused by pad deposits being left on the rotors in an uneven fashion. Besides improper lug nut torque or bad wheel bearings, one common reason for uneven pad deposits is if the pads were not properly bedded. If they were simply installed by the shop and then you never did any hard stops, they might not have bedded properly. Bedding pads requires repeated hard stops- some pad/rotor combos are more sensitive to bedding than others.
Last edited by alfaspider on Mon Mar 26, 2018 3:55 pm, edited 1 time in total.

N10sive
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Re: Recurring brake rotor problem

Post by N10sive » Mon Mar 26, 2018 3:55 pm

ZapRowsdower wrote:
Mon Mar 26, 2018 3:33 pm
telecaster wrote:
Mon Mar 26, 2018 3:14 pm
Severe over tightening of the lug nuts can cause this over time.

Those lug nuts should be tightened to a manufacturer specified range of ft lbs. Many mechanics put an impact gun on them and crank the snot out of them. Sometimes this can be 1.5x, 2x or more of the requirements. I've seen professional places do this on several occasions :(
+1, almost every time I have work done at a shop I have to adjust the lug nuts, usually after getting out my biggest breaker bar to loosen them.
+2

While often overlooked this is a big problem many don't know about that.

gmc4h232
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Re: Recurring brake rotor problem

Post by gmc4h232 » Mon Mar 26, 2018 4:01 pm

Rotors that are warped will pulsate during braking. This generates a vibration that can be felt in the brake pedal as well as the steering wheel. The level of vibration depends on the severity of the warping. I dont know if this is the grinding sensation you describe, but one fix is to have the rotors "turned" where a mechanic will resurface the rotor, making it perfectly flat again, which sounds like what your mechanic did. You only get so many turnings before the rotors should be replaced.

Warping of brake rotors is not caused by heat alone, they are made to heat up and cool down all day with no issues. The warping occurs when they heat up and then are cooled more rapidly than normal such as when driving through a good sized puddle.

Brake pads will wear unevenly when trying to clamp down on a warped rotor and could potentially lead to premature replacement. How many miles are on your vehicle and what percentage of that mileage is city vs highway? Higher percentage of city miles = higher braking amounts = shorter replacement interval.

alfaspider
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Re: Recurring brake rotor problem

Post by alfaspider » Mon Mar 26, 2018 4:17 pm

wrongfunds wrote:
Mon Mar 26, 2018 3:44 pm
Once you cut the rotors, you make it easier for them to wrap again. It is just the physics. Never let dealer cut the rotors, especially under warranty. Insists on getting new rotors instead.
Again, the rotors are not warping- pad residue is being deposited unevenly. You may be more likely to get uneven pad deposits after rotors are turned because the rotor surface is no longer the same uniformity or consistency as it was when new.

In any event, if you are paying a shop to do your brakes (instead of doing them yourself on a shoestring), it rarely makes sense to have rotors turned. In fact, due to the low cost, turning rotors is becoming increasingly rare. Unless you have a high performance car with an exotic rotor (like a carbon ceramic), they are quite cheap. You can get a nice pair (OEM+) for under $100 on many cars.

Jack FFR1846
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Re: Recurring brake rotor problem

Post by Jack FFR1846 » Mon Mar 26, 2018 4:24 pm

There are a number of possible causes and I'll ask some specific questions to see if I can help.

How many miles since the rotors were last machined?
How much time?

Some reasons that brakes can feel like they're grinding.
There could be actual rock or sand caught between the side of the brake pad and the metal slider (on each side of the brake pad as part of the caliper bracket). With most factory pads, these metal sliders (I'm sure there's another name, maybe retainers) are included with the pads so replacing them would remove any rock or sand.
Worn braking section on the rotor with build up of rust on the inner (most common) or outer part of the rotor. These are the areas beyond the swept area of the pad (where the pad is contacting the rotor). This typically occurs when the rotors are not machined or replaced and new pads are installed where the pad material might not line up with the worn part of the rotor and is sweeping the rusted part. The solution to this is to machine the rotors when replacing pads or replace rotors.

If you go very long time before driving the car and then only go a small distance, rust built up will feel like a grind until it's worn off. This can be especially bad if you park the car after the brakes have become wet (or the car is in a garage exposed to outside temps where condensation forms). Simply driving the car normally for some time will remove this. Rotors are steel and they will rust.

Pads tend to wear out at pretty regular mileage intervals. It's different for all cars, so I can't give you a number for your car. It's pretty cool that this dealer didn't make you pay for new pads the last time when they machined the rotors. Most places require both to be replaced at the same time. They don't have to.

Rotors have limited life and that's governed by minimum thickness that's stamped right on the rotor itself. So the machinist who turns the rotors will measure first. If he can't maintain this thickness after turning them, they'll tell you that you'll need to replace them.

Alfaspider has it completely right. Build up of pad material is very often mistakenly called a warped rotor. Simply sanding the rotors can solve this for the DIY guy, but for a paid mechanic, it's not cost effective. He's going to replace or turn them which will remove the built up pad material.
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samtex
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Re: Recurring brake rotor problem

Post by samtex » Mon Mar 26, 2018 11:50 pm

After the repair, have the rotors checked for lateral run out. Usually it should be .002" max. The hubs could be off or the rotors may not be flush on the hubs (check for any debris). Since virtually no technician wants to spend the time to check rotor run out, this can happen.

If you have a lateral run out issue, the brake pads work like a lathe and removes the high areas of the rotor, ultimately causing the pulsing. Even experienced technicians can be fooled the first time (or the 2nd, 3rd...) the job comes back.

Samtex

Doug E. Dee
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Re: Recurring brake rotor problem

Post by Doug E. Dee » Tue Mar 27, 2018 7:55 am

I had to put a 4' cheater pipe on my lug wrench to loosen them after I had new tires installed. I would have been stranded if I had a flat and was depending on the cheesy OEM lug wrench.

Maybe the OP could try cleaning his rotors with sandpaper to remove any deposits.

edge
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Re: Recurring brake rotor problem

Post by edge » Tue Mar 27, 2018 8:32 am

I don't follow. Rotors are a wear item. Replace them.
newbie003 wrote:
Mon Mar 26, 2018 2:47 pm
I've been having an issue with our 2014 Buick Enclave, where last year we had to have the brake rotors ground(?) as they were causing a grinding sensation when braking.  A year later it's doing it again.

Buick says they'll fix the rotors for free again (still under warranty) but they now say I need new brakes as well (I guess new brake pads, I'm not certain, I have to call them back).

So, 2 questions:

1.  What might the underlying reason be why the rotors keep needing to be ground down?  After this year it's out of warranty and I'm worried this will happen again next year.

2.  Is it likely (or at least plausible) that I need to new brakes due to the bad rotors?  I want to fight for them to pay for the brakes as well, if I can claim that the bad rotors caused the brakes to wear too quickly.

Thanks for any thoughts!

barnaclebob
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Re: Recurring brake rotor problem

Post by barnaclebob » Tue Mar 27, 2018 8:47 am

edge wrote:
Tue Mar 27, 2018 8:32 am
I don't follow. Rotors are a wear item. Replace them.
Rotors don't wear nearly as much as pads and should last a very long time. I might still have the OEM rotors on my 2001 with 160k miles.

Jack FFR1846
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Re: Recurring brake rotor problem

Post by Jack FFR1846 » Tue Mar 27, 2018 8:51 am

Doug E. Dee wrote:
Tue Mar 27, 2018 7:55 am
I had to put a 4' cheater pipe on my lug wrench to loosen them after I had new tires installed.
I'd avoid wherever you had the install done. 80 foot pounds is about average for max torque on lug nuts. This requires only about 9 inches of lug wrench for an average person. Putting lug nuts on with a monster impact gun not only distorts the rotors, it stretches the studs and can potentially stretch them enough that they break the next time the nuts are removed. This is auto mechanics 101, but unfortunately, lots of "professional" mechanics haven't passed that.
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neilpilot
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Re: Recurring brake rotor problem

Post by neilpilot » Tue Mar 27, 2018 8:53 am

barnaclebob wrote:
Tue Mar 27, 2018 8:47 am
edge wrote:
Tue Mar 27, 2018 8:32 am
I don't follow. Rotors are a wear item. Replace them.
Rotors don't wear nearly as much as pads and should last a very long time. I might still have the OEM rotors on my 2001 with 160k miles.
Actually I have the OEM rotors and pads, with significant life left on the pads, front & back. On my 2008 with 145k miles. Somewhat amazing.

ZapRowsdower
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Re: Recurring brake rotor problem

Post by ZapRowsdower » Tue Mar 27, 2018 3:52 pm

Jack FFR1846 wrote:
Tue Mar 27, 2018 8:51 am
Doug E. Dee wrote:
Tue Mar 27, 2018 7:55 am
I had to put a 4' cheater pipe on my lug wrench to loosen them after I had new tires installed.
I'd avoid wherever you had the install done. 80 foot pounds is about average for max torque on lug nuts. This requires only about 9 inches of lug wrench for an average person. Putting lug nuts on with a monster impact gun not only distorts the rotors, it stretches the studs and can potentially stretch them enough that they break the next time the nuts are removed. This is auto mechanics 101, but unfortunately, lots of "professional" mechanics haven't passed that.
That's for sure, I've had to replace two studs so far for exactly that reason. And on some cars that requires a fair amount of disassembly to do. At this point I only have vehicles go in for free services(when new) or inspections(unavoidable). So far, I've found that 90% of the places I've tried put way too much torque on them.

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munemaker
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Re: Recurring brake rotor problem

Post by munemaker » Tue Mar 27, 2018 3:57 pm

newbie003 wrote:
Mon Mar 26, 2018 2:47 pm
I've been having an issue with our 2014 Buick Enclave, where last year we had to have the brake rotors ground(?) as they were causing a grinding sensation when braking.  A year later it's doing it again.
This is one of the major reasons I quit buying GM cars (recurring problems with brakes and rotors, with both OEM and aftermarket parts, on a variety of GM vehicles).

Shops are always going to replace pads when the rotors are replaced. It is considered good practice.

The rotors are supposed to last through several sets of pads. On our GM cars, the rotors would wear out before the pads.

I switched to Hondas and brake service averages around 65,000 miles.

THY4373
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Re: Recurring brake rotor problem

Post by THY4373 » Tue Mar 27, 2018 3:57 pm

alfaspider wrote:
Mon Mar 26, 2018 3:53 pm

This is actually a myth. Your brake fluid will boil off and/or pads will melt into a puddle long before the rotors would ever get hot enough to physically warp. I have boiled high-temp racing brake fluid on the track without warping rotors. Some reading by a leading brake manufacturer:
While I tend to agree rotor warping is overstated and pad deposits are probably the cause of a lot of warped rotor complaints, I did have a rear rotor on my 2010 Lincoln MKZ that was obviously warped it was obvious to the naked eye (I replaced it myself). No idea how it got that way since the warping happened before I got the car but I have zero doubt it was a warped rotor.

AJS
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Re: Recurring brake rotor problem

Post by AJS » Tue Mar 27, 2018 4:06 pm

Agree, fix the problem by purchasing a Honda, Toyota or Subaru. Not sure why anyone buys a GM car.
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runner3081
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Re: Recurring brake rotor problem

Post by runner3081 » Tue Mar 27, 2018 8:29 pm

barnaclebob wrote:
Mon Mar 26, 2018 2:50 pm
The brakes on my altima make a grinding/groaning noise under hard braking but both the pads and rotors look fine and performance is good so I've just lived with it. Its not an earsplitting or cringe inducing kind of noise. Coming up on 90k miles for the OEM pads and they'll need to be changed soon anyway. Maybe that will fix it.

Do your rotors look normal?

Is it a grinding sensation or a pulsing sensation?
Same issue on my Nissan made Infiniti.

Never had an issue, then had OEM pads and rotors done. Started grinding, intermittently and at lower speeds. The shop felt it as well and replaced everything again, still have the issue. There is no deterioration in braking, so I just deal with it.

zkzkzk
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Re: Recurring brake rotor problem

Post by zkzkzk » Wed Mar 28, 2018 8:05 am

alfaspider wrote:
Mon Mar 26, 2018 4:17 pm
wrongfunds wrote:
Mon Mar 26, 2018 3:44 pm
Once you cut the rotors, you make it easier for them to wrap again. It is just the physics. Never let dealer cut the rotors, especially under warranty. Insists on getting new rotors instead.
Again, the rotors are not warping- pad residue is being deposited unevenly. You may be more likely to get uneven pad deposits after rotors are turned because the rotor surface is no longer the same uniformity or consistency as it was when new.

In any event, if you are paying a shop to do your brakes (instead of doing them yourself on a shoestring), it rarely makes sense to have rotors turned. In fact, due to the low cost, turning rotors is becoming increasingly rare. Unless you have a high performance car with an exotic rotor (like a carbon ceramic), they are quite cheap. You can get a nice pair (OEM+) for under $100 on many cars.
In the StopTech article you posted the link to to the author states that he has never encountered a warped brake rotor but that is "presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification"
Although I do agree that the majority of what people call "warped" rotors are a material transfer issue I believe a brake rotors can and do actually warp.
That said I have had good look with high carbon as well as cryogenically treated rotors in the past, provided they were properly bedded.

neilpilot
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Re: Recurring brake rotor problem

Post by neilpilot » Wed Mar 28, 2018 8:16 am

zkzkzk wrote:
Wed Mar 28, 2018 8:05 am

That said I have had good look with high carbon as well as cryogenically treated rotors in the past, provided they were properly bedded.
I've DIYed all of my brake repairs for decades, and have always bedded the new pads with or without new rotors. Based on discussions with other DIY owners and also with those who use repair shops or dealer maintenance, it's my opinion that many (maybe most) do not bed the new pads properly, if at all. Many owners have no idea that there is even a bedding process.

I agree that bedding is vital to ensure optimum braking, although it will not address the noise issues discussed in this thread.

Jack FFR1846
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Re: Recurring brake rotor problem

Post by Jack FFR1846 » Wed Mar 28, 2018 8:29 am

Just a data point. I'm currently replacing rear brakes on 2 of my cars. 13 Subaru Crosstrek and 04 Subaru Outback. I have been looking for a good (cheap) way to deal with the rotors as I don't want either car down long. I found that dealer rotors are $68 each, $58 at the discount dealer subarugenuineparts.com. Somewhat similar at autozone. I can have them turned for $21 each. And finally, I checked Rock Auto. Wow! $12 each. With shipping, I got all the rotors for $68 for 2 cars. I fortunately am right at the end of the Auto Zone wear out warranty (2 years) on the pads so get them free for this changeover (I changed them 2 years ago myself). For do it yourselfers, this is a great option.
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Crow Hunter
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Re: Recurring brake rotor problem

Post by Crow Hunter » Wed Mar 28, 2018 9:27 am

Something I can help with!

I was in the business of manufacturing rotors/hubs as a Tier 1 supplier for over 7 years.

NVH can be caused by multiple factors. It could be anything from a convex mounting surface on the hub interface on the inside of the "top hat" to a lateral runout problem on the rotors themselves to a 2-5th order harmonic that happens to match the natural frequency of your chassis to a casting defect causing carbides to form in the rotor that are causing uneven wear to an improperly specified pad material that isn't aggressive enough resulting in "balling" of material on the rotor surface. (I have seen all of these before)

Or it could be as simple as someone driving it has a bad lead foot. :)

What, exactly are you experiencing?

Grinding vs pulsing vs groan vs wheel shake are all caused by completely different factors.

If you can give specifics on what you are experiencing, I might be able to help you narrow it down.

ETA:

PSA, if you are looking to buy replacement rotors, look for a WF stamp on the inside of the top hat in the non-machined area close to where the minimum thickness is called out. That represents Wapauca Foundry manufacturing. In all of our testing, they were the only supplier that could pass a DT140 test without cracking/breaking the rotors. All the Chinese rotors we ever tested failed spectacularly. WF foundry parts crazed but never failed.

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