Nearly New Rotors and Brake Pulsation

bunnspecial

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Well, ~250 miles after bedding in fixed the pulsation, it came back.

No time this week to do brakes, but I'll grab 4 OEM rotors and OEM front and rear pads and toss them all on.
 
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Had a similar issue recently as well. I simply took the rotors and had them turned and kept the brake pads since they didn't even have 200 miles on them. They guy who did it said it was becoming more and more common for people to bring in brand new rotors to be turned before installing them.

I've never seen anybody successfully re-bed-in brakes after a pulsation developed. If they have a pulsation issue, the rotors should be resurfaced...THEN do another bed-in.
 
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Had a similar issue recently as well. I simply took the rotors and had them turned and kept the brake pads since they didn't even have 200 miles on them. They guy who did it said it was becoming more and more common for people to bring in brand new rotors to be turned before installing them.

I've never seen anybody successfully re-bed-in brakes after a pulsation developed. If they have a pulsation issue, the rotors should be resurfaced...THEN do another bed-in.


Turning the rotor makes the problem reappear quicker.

The rotor is a heatsink and a combination of mismatched pad material and rotor heat ranges caused pad material to imprint /weld itself to the surface.

With less material to absorb heat, the rotor now heats up even quicker than prior to the turn and accelerates the " non uniform pad imprinting problem"
 
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Turning the rotor makes the problem reappear quicker.

The rotor is a heatsink and a combination of mismatched pad material and rotor heat ranges caused pad material to imprint /weld itself to the surface.

With less material to absorb heat, the rotor now heats up even quicker than prior to the turn and accelerates the " non uniform pad imprinting problem"
Even within spec?
 
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less mass is less mass regardless of spec- "spec" is designed to avoid cracks vs prevent pad imprinting.
There may be less mass, but if the rotors are not exposed to extreme conditions, it may not matter.

From what I have seen, properly machined rotors deliver comparable service life to new rotors.
 
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Turning the rotor makes the problem reappear quicker.

The rotor is a heatsink and a combination of mismatched pad material and rotor heat ranges caused pad material to imprint /weld itself to the surface.

With less material to absorb heat, the rotor now heats up even quicker than prior to the turn and accelerates the " non uniform pad imprinting problem"
That has never been my experience. Most every pad imprinting to rotor issue I've ever seen was a result of improper bed-in. I've "fixed" a lot of other people's mistakes over the years just by resurfacing and reusing the existing rotors as long as they were in spec and proper bed-in procedure. Those people reported years of trouble free, smooth braking.
 
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That has never been my experience. Most every pad imprinting to rotor issue I've ever seen was a result of improper bed-in. I've "fixed" a lot of other people's mistakes over the years just by resurfacing and reusing the existing rotors as long as they were in spec and proper bed-in procedure. Those people reported years of trouble free, smooth braking.

I wish that worked for me.

Ive had pad imprinting problems on 3 different trucks in the last 15 years. (titan, ridgeline, Chevy 3500 dmax)

In each truck they were turned and put back together with OE parts bedded per instruction, and the problem reappeared in a shorter span of miles. It was a total waste of time and money to bother doing it at all.

in each rig the problem went away with Hawk LTS pads and aftermarket rotors.. (stillen / Rotor pros on the titan, and stop techs on the other two)

No amount of turning or bedding regardless of how proper will fix a poorly matched pad combo for any length of time.
 
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I wish that worked for me.

Ive had pad imprinting problems on 3 different trucks in the last 15 years. (titan, ridgeline, Chevy 3500 dmax)

In each truck they were turned and put back together with OE parts bedded per instruction, and the problem reappeared in a shorter span of miles. It was a total waste of time and money to bother doing it at all.

in each rig the problem went away with Hawk LTS pads and aftermarket rotors.. (stillen / Rotor pros on the titan, and stop techs on the other two)

No amount of turning or bedding regardless of how proper will fix a poorly matched pad combo for any length of time.
Depends on the manufacturer. For most manufacturer choice of supplier and material always comes down to money.
Size? My Prado in Europe has undersized rotors. No OE rotors are working if vehicle is driven bit aggressivly. Aftermarket parts (EBC) resolved that issue after 3-4 attempts using Toyota OE parts. I had same issue with SIenna when bought it slightly used. Did not even bother with OE parts, just went EBC, and after that Raybestos rotors and Pagid pads (also works).
On BMW and VW pretty much anything works, OE or OEM. Aftermarket like Centrict etc. I do not know as OEM parts are pretty chep to go that route. Only aftermarket I tried on these vehicles is EBC on VW (works excellent) and EBC Yellowstuff on BMW I got for free from EBC to try on track (works good so far).
 
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Depends on the manufacturer. For most manufacturer choice of supplier and material always comes down to money.
Size? My Prado in Europe has undersized rotors. No OE rotors are working if vehicle is driven bit aggressivly. Aftermarket parts (EBC) resolved that issue after 3-4 attempts using Toyota OE parts. I had same issue with SIenna when bought it slightly used. Did not even bother with OE parts, just went EBC, and after that Raybestos rotors and Pagid pads (also works).
On BMW and VW pretty much anything works, OE or OEM. Aftermarket like Centrict etc. I do not know as OEM parts are pretty chep to go that route. Only aftermarket I tried on these vehicles is EBC on VW (works excellent) and EBC Yellowstuff on BMW I got for free from EBC to try on track (works good so far).

No one would turn my BMW rotors, I was told repeatedly that the rotors and pads are designed to wear and be replaced as a set.


Growing up I didnt turn rotors unless I had a problem or a lip/ groove,
Id replace the pads and burnish surface and move on - did that for decades with zero problems.
 
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No one would turn my BMW rotors, I was told repeatedly that the rotors and pads are designed to wear and be replaced as a set.


Growing up I didnt turn rotors unless I had a problem or a lip/ groove,
Id replace the pads and burnish surface and move on - did that for decades with zero problems.
BMW changed that policy as people wanted that all the time.
I never do that. Front ATE, Textar, Pagid, Jurid rotors (all OE suppliers for BMW) are in the range of $50-60 per piece. Why doing it?
 
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BMW changed that policy as people wanted that all the time.
I never do that. Front ATE, Textar, Pagid, Jurid rotors (all OE suppliers for BMW) are in the range of $50-60 per piece. Why doing it?

my BMW rotors were also pretty soft and had a significant lip by replacement time, so there were really two issues at play.

one - of the policy at the time...interesting to hear they changed it.
two- there wasnt much left to turn anyway.

The upside was the performance - they performed very well.
 
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my BMW rotors were also pretty soft and had a pretty good lip by replacement time, so there were really two issues at play.

one - of the policy at the time...interesting to hear they changed it.
two- there wasnt much left to turn anyway.

The upside was the performance - they performed very well.
Yeah, BMW does not joke around that.
 
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Why would you even keep those junky rotors? The grooves in them will damage the new pads.
Any new rotor is fine, maybe get one with a coated hat (rust proof). A rotor isn't something that can be screwed up with modern tool/machines, even on Chinese brands.
The pads, on the other hand, are a different animal. They are to blame for 99% of the "pulsation in brake pedal" issues, but people keep blaming the "warped rotors", because they don't understand the process.

The brake pads deposit a layer of braking material on the discs.
That layer needs to be uniform and thermally stable. That's why the quality of pads and initial bedding of the pads is extremely important!
Even "good" pads, if they are not bedded per manufacturer instructions, will go "bad". It isn't just a "slap and go" type of deal.

Any in-uniformity on the deposited layer will only accentuate with every braking action (material will be deposited more in places where there is already more material, because that's where the heat will be generated). And so, the pulsation will appear after a few hundred miles driven (in the city), with about a thousand braking actions.
Staying at stop light, with foot hard pressed on fresh and not bedded pads, will just print those pads on the hot steel rotors. That's the main source of pulsation.

Get quality pads, from reputable manufacturers, even if they cost a bit more. Or even get OEM pads, usually they are good. I gave up on using "store brand" pads, they didn't work for me.
When I change my pads I also order new rotors. They are so cheap and I am doing this every 10 years, so why use rusted and f-t up rotors? They will just damage the new pads!
I could't agree with you more, initial bed-in following ALL pad manufacturer's process, never clean new rotors with brake clean wash them with dish soap, many causes of pulsation, sticking slides, the corroded piston in caliper, corroded bore in caliper,
 
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BMW changed that policy as people wanted that all the time.
I never do that. Front ATE, Textar, Pagid, Jurid rotors (all OE suppliers for BMW) are in the range of $50-60 per piece. Why doing it?
Aftermarket Euro brand rotors have always been unusually inexpensive for European cars. Not sure why.
With that said, at the dealer level, the new BMW’s seem to use a less aggressive pad compound that no longer wears rotors as terribly. On car brake lathes are now being used at the dealer level for brake services when possible, especially under prepaid maintenance.
 
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Aftermarket Euro brand rotors have always been unusually inexpensive for European cars. Not sure why.
With that said, at the dealer level, the new BMW’s seem to use a less aggressive pad compound that no longer wears rotors as terribly. On car brake lathes are now being used at the dealer level for brake services when possible, especially under prepaid maintenance.
I got few days ago Zimmerman's front rotors to switch to after track season from ATE. Made in Germany and I think they were $55 a piece.
With F series line up BMW switched base models to ceramic I think. The reason was complaints about dusting bcs. most BMW customers that lease vehicles are more worried about the looks of the wheels than performance.
They also offered M performance brakes that use more aggressive compounds but also add to price. So F30 335 uses generally 340x30mm rotor with Brembo front calipers, regular calipers in the back. But M performance brakes get 370X30mm rotor, and rear calipers are also Brembo 2-piston. But for base models there are enough aftermarket pads that are more aggressive and still fairly cheap.
So they kind of offered both worlds, but really confused the heck out of ordering spare parts.
 
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I had this same problem on an F150. It happened almost immediately after the truck was lifted for a wheel balance. The rotors were replaced in 300 miles, and it happened again in less than 2k miles. Turns out, that when the truck was lifted the first time, the brake lines stretched and constricted. I replaced the front brake lines, and have driven 70k miles since... hmm.
 

bunnspecial

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Even after bedding a couple of times, the vibration would mostly go away briefly, then come back seemingly worse than before.

I popped into the local Ford dealer this morning and left with Motorcraft pads and rotors for all 4 wheels. Total cost was ~$400.

I did the fronts this afternoon-rears will need to wait for tomorrow. It's a night and day difference, though. In fact at first it kind of unnerved me that there's ZERO detectable vibration even at 80mph, and probably mostly because I'm just so use to it being there.

BTW, I'd have probably done them all if I hadn't gotten sidetracked for a while with a stripped head and stuck screw holding one of the old rotors on. I generally replace these-even though I know they were mostly an assembly line part until the wheels made it on, I like having them in there as I find it makes it easier to get the pad bracket and pads back in place(and the pads maneuvered into the clips) when the rotor is being held against the hub and not flopping. It was a moot point, though, since the replacement rotors weren't drilled for them.

I don't know that the rears need to be done, but the parts are here and they are older/higher mileage than the almost new fronts I replaced.

I was also long overdue for an oil change, so while I was working on the passenger side brakes it was nice to just reach over and undo the drain plug and let it go while I was doing other stuff.
 
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