# Brake Vibration



## kennykenny (Sep 23, 2007)

I have a 2003 Taurus SE sedan. When the brake pedal is pressed to begin the car slow down, there is a vibration felt within the brake pedal. As the car slows down more, the vibration goes away. I recently replaced the rear drum brakes. Could that have anything to do with the vibration? Other things to check or is this normal? Thanks.


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## Nealtw (Jun 22, 2017)

Any time I have done what i call a panic stop I get a pulsing in the peddle from the anti lock breaks for some time after. 

You could also have a warped rotor in the front.
Some new drums need turning before you use them.


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## Mike Milam (Mar 3, 2017)

Not normal. Have you looked at the front brakes? The rotors on these late models do warped quite often when they wear. For what replacements cost, I usually just replace pads and rotors at the same time.
Our 2011 Mazda CX7 was doing that so I just ordered a kit that included both rotors and pads. Smooth as silk now.


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## kennykenny (Sep 23, 2007)

Mike Milam said:


> Not normal. Have you looked at the front brakes? The rotors on these late models do warped quite often when they wear. For what replacements cost, I usually just replace pads and rotors at the same time.
> Our 2011 Mazda CX7 was doing that so I just ordered a kit that included both rotors and pads. Smooth as silk now.


I did not look at the front brakes. If the front pads look like they have enough surface left, it could possibly be the front rotors? 

As Neal said, new drums sometimes need turning before using them?


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## iamrfixit (Jan 30, 2011)

Most likely front rotors have become warped. They can warp no matter the condition of the brake pads. This has almost become normal any more, the rotors on modern vehicles are so thin or cheaply made. 

Excessive high speed or hard braking, even installing more aggressive brake pads can accelerate warping. In the past you could have them turned if they weren't worn or warped beyond spec, but the expense to have that done nearly exceeds the cost to just replace them.


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## Nealtw (Jun 22, 2017)

iamrfixit said:


> Most likely front rotors have become warped. They can warp no matter the condition of the brake pads. This has almost become normal any more, the rotors on modern vehicles are so thin or cheaply made.
> 
> Excessive high speed or hard braking, even installing more aggressive brake pads can accelerate warping. In the past you could have them turned if they weren't worn or warped beyond spec, but the expense to have that done nearly exceeds the cost to just replace them.


A while ago I told a friend she needed them turned and she did, a year later I felt bad telling her to have them changed out.


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## de-nagorg (Feb 23, 2014)

If your rotors got hot from use, and you hit a puddle somewhere, you got warped rotors, especially on the modern cheap junk sold now. 

And pulsate they will do, There is supposed to be a proportioning valve in the brake line, between the front and rear system.

Sometimes this is faulty, and the two different pressures fight with each other, and you feel it in the pedal.

Most likely this is not your problem, the car is not that old yet.

Check those rotors with a straight edge, the metal ruler from your combination square is perfect for this.

And if you find a high spot or two, you have a choice, live with it, turn them, or replace them.


ED


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## Porsche986S (Dec 10, 2017)

kennykenny said:


> I have a 2003 Taurus SE sedan. When the brake pedal is pressed to begin the car slow down, there is a vibration felt within the brake pedal. As the car slows down more, the vibration goes away. I recently replaced the rear drum brakes. Could that have anything to do with the vibration? Other things to check or is this normal? Thanks.


Did the vibration show up right after the rear drum work ? When you say you replaced the rear drum brakes what does that mean ? Just the shoes or shoes and new drums ? Aprox. how many miles on the current front pads/discs ?


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## huesmann (Aug 18, 2011)

So much misinformation about "warped" rotors...when odds are it's just glazed pad deposits.


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## kennykenny (Sep 23, 2007)

huesmann said:


> So much misinformation about "warped" rotors...when odds are it's just glazed pad deposits.


If it is "glazed pad deposits," is this something that can be "cleaned?" Spray down the pads with brake clean?


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## DexterII (Jul 14, 2010)

Playing the odds, drum versus disk, what you described is most likely the front brakes. But since you recently did the rears, did you pre-adjust them? Drum brakes have self adjusters, but I do not believe they will self adjust if the shoes are not engaging the drums to start with, so although I don't recall actually seeing this I can sort of see the shoes skating on the backing plate some if they're not fully engaging. Just a thought, and if you did pre-adjust them they should be fine and I would focus on the front ones.


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## kennykenny (Sep 23, 2007)

DexterII said:


> Playing the odds, drum versus disk, what you described is most likely the front brakes. But since you recently did the rears, did you pre-adjust them? Drum brakes have self adjusters, but I do not believe they will self adjust if the shoes are not engaging the drums to start with, so although I don't recall actually seeing this I can sort of see the shoes skating on the backing plate some if they're not fully engaging. Just a thought, and if you did pre-adjust them they should be fine and I would focus on the front ones.


I did adjust them when installing. I used a brake resetting gauge when installing to help adjust correctly.


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## DexterII (Jul 14, 2010)

Good, and I figured as much as it sounds like you're pretty thorough, but just brainstorming a bit. So I would consider them good and focus on the front ones.


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## iamrfixit (Jan 30, 2011)

Rear brakes out of adjustment will make the pedal go down further, closer to the floor. A second pump of the brakes will add more fluid to the circuit and bring the pedal up. I've never seen a case where drum brakes caused a pedal pulsation. 

Deposits or glaze on the rotor doesn't usually cause pulsation in the pedal. It might cause brake fade because they heat up faster and hot brakes can sure lead to warped rotors. Might also cause uneven braking, where the vehicle seems to surge as the brake is applied due to an uneven friction surface of the rotor. To get rid of that you'd need to mechanically finish the surface. Have the rotor turned or scuff both the rotor and pads to remove any glaze or deposits.

A strong pedal pulsation is most often a warped, usually front, rotor. Easy to check if you have the right tools. Probably undetectable with a straight edge but a dial indicator can reveal it very easily. You could also remove the rotors to have them turned and they can easily detect warp when the rotor is put on the lathe. Or you could just throw on a set of rotors for about $60/pair on the average car. Always best in a proper brake job to replace both pads and rotors to get the best results. The finish on the rotor is important for proper break in of the pads.


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## raylo32 (Nov 25, 2006)

Take a good look at them first. What can happen is if you come to a stop and hold the brake pedal down when your rotors and pads are hot from some previous hard braking the pads can leave little pad shaped deposits. These alternate with clean rotor surface and that change in friction as the rotor turns creates pulsation. If you don't see anything like this check the run out and maybe the rotors are warped. But that is unlikely unless you let them get below specified thickness and got them really hot. If that doesn't work, get 'em turned or replace them.

If you see those deposits you can sometimes smooth them off a bit with a sander. Then go out and bed the pads with a series of smooth but firm stops... and drive for awhile after to cool the brakes before stopping and recreating the same problem again.

It could also be the same sort of thing from the drums. When you say you "replaced the rear drum brakes" what exactly did you do, or have done? If you just slapped in new shoes without replacing or turning the drums they could be the culprit.




kennykenny said:


> If it is "glazed pad deposits," is this something that can be "cleaned?" Spray down the pads with brake clean?


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## ukrkoz (Dec 31, 2010)

kennykenny said:


> If it is "glazed pad deposits," is this something that can be "cleaned?" Spray down the pads with brake clean?



Yes. I just cleaned mine on 98 MGM. It takes rotor removal, setting it on a sturdy surface and taking angle grinder or cut off tool with sanding disk to the rotor. Then, getting it back to clean metal in circular motion.


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## kennykenny (Sep 23, 2007)

raylo32 said:


> Take a good look at them first. What can happen is if you come to a stop and hold the brake pedal down when your rotors and pads are hot from some previous hard braking the pads can leave little pad shaped deposits. These alternate with clean rotor surface and that change in friction as the rotor turns creates pulsation. If you don't see anything like this check the run out and maybe the rotors are warped. But that is unlikely unless you let them get below specified thickness and got them really hot. If that doesn't work, get 'em turned or replace them.
> 
> If you see those deposits you can sometimes smooth them off a bit with a sander. Then go out and bed the pads with a series of smooth but firm stops... and drive for awhile after to cool the brakes before stopping and recreating the same problem again.
> 
> It could also be the same sort of thing from the drums. When you say you "replaced the rear drum brakes" what exactly did you do, or have done? If you just slapped in new shoes without replacing or turning the drums they could be the culprit.


I replaced, myself, the drums and all of the hardware as well.


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## kennykenny (Sep 23, 2007)

Porsche986S said:


> Did the vibration show up right after the rear drum work ? When you say you replaced the rear drum brakes what does that mean ? Just the shoes or shoes and new drums ? Aprox. how many miles on the current front pads/discs ?


My son drives the car for the most part and he told me that the brakes have been pulsing for "a while." Whatever that means. That would mean before I did the ream brakes. On the rear brakes, I replaced the drums and complete new hardware. The front brakes were replaced 6/16 and have approximately 30,000 miles on them.


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## Porsche986S (Dec 10, 2017)

kennykenny said:


> My son drives the car for the most part and he told me that the brakes have been pulsing for "a while." Whatever that means. That would mean before I did the ream brakes. On the rear brakes, I replaced the drums and complete new hardware. The front brakes were replaced 6/16 and have approximately 30,000 miles on them.


If that's the case I would purchase another set of front brake pads , clean the rotors with brake clean and bed in the new pads . Pads are relatively cheap and easy to replace . If the vibration doesn't go away with new pads check the rotors for runout if you have a dial indicator . Could be a worn suspension piece also . You have to check/analyze as you go to solve the problem . Good luck


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## Mike Milam (Mar 3, 2017)

My time is more important to me than the cost of rotors. Just replace them and move on to the next project.

Looked on AutoZone's site and they are 37.00 USD each.


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## kennykenny (Sep 23, 2007)

Mike Milam said:


> My time is more important to me than the cost of rotors. Just replace them and move on to the next project.
> 
> Looked on AutoZone's site and they are 37.00 USD each.


Totally agree. Just attempting to find out the correct thing to repair rather than blindly replacing things that might not fix the issue.


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## Mike Milam (Mar 3, 2017)

kennykenny said:


> Totally agree. Just attempting to find out the correct thing to repair rather than blindly replacing things that might not fix the issue.


Pulsing brake pedal and/or vibration is most often warped rotors. Crazy as it sounds a long hard panic stop can warp them.


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## huesmann (Aug 18, 2011)

Smh...


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## raylo32 (Nov 25, 2006)

Agree. But it's hard to fight such an entrenched myth.



huesmann said:


> Smh...


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## raylo32 (Nov 25, 2006)

Bottom line, whatever the cause you're easiest path forward that will give you best and fastest results is to replace the front rotors and pads. This stuff isn't expensive. And think about how you drive and brake to try to prevent a recurrence. Especially try not to stay stopped immediately after some very hard braking. Best to let the brakes cool a bit.


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## iamrfixit (Jan 30, 2011)

Well, I usually verify warp with a dial indicator. The rotors on my F250 are probably $135 or so for a pair and the lifetime warranty has always covered them. First thing they do is mount them on the brake lathe. Of course they verify they're warped and then they give me a new pair. Probably up to 6 sets over 15 years. New manager tried to not cover it the last time. Called it a manufacturer defect warranty. After we had a bit of a discussion and a couple phone calls, I got new rotors.


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## raylo32 (Nov 25, 2006)

Here is a decent treatise on the subject. Pad deposits and uneven rotor surface wear will present as runout if you check only one side but unless you have equal and opposite runout in the same direction on the other side at the same exact places your rotors are not "warped". The pulsating effect and the remedies may be the same depending on how much work you want to do but the rotors should not warp unless they get to be below standard thickness and/or are seriously abused. Shops may use the term warp because it makes it a nice easy sound bite to explain to customers.

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


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## iamrfixit (Jan 30, 2011)

I can buy the uneven rotor wear, with the level of runout I've found on my rotors there's no way I could believe it might be deposits. I'm *not* gonna go after my rotors with a sanding wheel trying to correct that level of runout. 

I would and I have had them turned, but the cost to do that anymore pretty much exceeds the cost to replace the rotors (in most cases). I've tried numerous times to have rotors turned that results in being told they're beyond spec. Whether they are warped or have uneven wear, pretty much the same solution. I replace them.


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## raylo32 (Nov 25, 2006)

Yup, the remedy is the same. And you really can't turn them very much or they will be below spec. Plus the rotors are cheap enough these days that turning just isn't cost effective to make sense.



iamrfixit said:


> I can buy the uneven rotor wear, with the level of runout I've found on my rotors there's no way I could believe it might be deposits. I'm *not* gonna go after my rotors with a sanding wheel trying to correct that level of runout.
> 
> I would and I have had them turned, but the cost to do that anymore pretty much exceeds the cost to replace the rotors (in most cases). I've tried numerous times to have rotors turned that results in being told they're beyond spec. Whether they are warped or have uneven wear, pretty much the same solution. I replace them.


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## kennykenny (Sep 23, 2007)

It sounds like replacing the rotor/pads are the way to go. Other than cleaning off the rotors prior to install, there is nothing else that should be done to them right?


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## raylo32 (Nov 25, 2006)

Give 'em a good spray with brake cleaner and wipe em off. Then you really should season the new rotors and burnish/bed the pads in for best life. There are various ways to do it but generally just a series of stops starting easy and getting a little firmer with cooling periods (very important!) between sets. Google for it and you will find plenty. Of course most brake jobs people just pick them up from the shop and drive normally and seem to do OK... or not??



kennykenny said:


> It sounds like replacing the rotor/pads are the way to go. Other than cleaning off the rotors prior to install, there is nothing else that should be done to them right?


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## kennykenny (Sep 23, 2007)

raylo32 said:


> Give 'em a good spray with brake cleaner and wipe em off. Then you really should season the new rotors and burnish/bed the pads in for best life. There are various ways to do it but generally just a series of stops starting easy and getting a little firmer with cooling periods (very important!) between sets. Google for it and you will find plenty. Of course most brake jobs people just pick them up from the shop and drive normally and seem to do OK... or not??


Thanks for that information. You are right, I'm sure that most people just pay, get the keys and drive off. Does doing it that way potentially shorten the life of the pads/rotors??? Just a thought?


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## kennykenny (Sep 23, 2007)

raylo32 said:


> Give 'em a good spray with brake cleaner and wipe em off. Then you really should season the new rotors and burnish/bed the pads in for best life. There are various ways to do it but generally just a series of stops starting easy and getting a little firmer with cooling periods (very important!) between sets. Google for it and you will find plenty. Of course most brake jobs people just pick them up from the shop and drive normally and seem to do OK... or not??


I've checked out a few videos on how to brake bed new brakes. Not sure if this is ticky tack but most videos say when slowing down from the high speed, DO NOT come to a complete stop before speeding back up before repeating the process while some others say to come to a complete stop and then speed back up. Does it matter one way or another, stop or no stop when braking them pads/rotors in?


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## raylo32 (Nov 25, 2006)

Best to keep rolling if you can during the process... but if you have to stop while the brakes are hot avoid holding the brake pedal down.


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