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Just picked up my 2018 challenger scat pack and noticed a brake pulsation at higher speeds. took it back to the dealer and they said they cant find anything wrong. Has any body had this problem.
 

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Hello. Welcome to the forum.


Pulsation in the pedal while braking? Certainly sounds like a rotor needing to be cut. But to answer your question. NO.


Btw. We usually say hello before we start in on the questions. Good luck!
 

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Welcome from So Cal........I had a high speed problem on a car once, wouldn't do it unless you drove 70 or over.
Dealer told me they aren't allowed to break the speed limit to test drive cars so they couldn't diagnose it.:icon_rolleyes:

I agree with the rotor comment.
 

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Pulsing at the brake pedal while applying the brakes is probably due to uneven material deposition from the pads to the rotor.

I had this happen once with my VW Golf TDi. I washed the car then failed to drive it afterwards to dry the brakes.

The next day I took the car out and after just a mile or two down the road had to make an emergency braking action to avoid a car that ran a stop sign. I bought the Golf to a very quick stop but safely and contact was avoided.

However, afterwards I noticed under rather light braking the brakes now pulsed.

What had happened is with rust the rotors had developed and which had not been rubbed away by braking before the panic stop the hard braking and leaving the brakes applied after the panic stop resulted in some pad material being left on the rotors.

I tried bedding in the brakes but this didn't help. The only solution was new rotors or having the "old" rotors surfaced.

But I found the pulsing only was present under light braking and my braking technique is to avoid light braking when possible. A bit harder braking delivers better brake life in my experience. So I continued to drive the car and really kind of forget about the brake pulsing until at around 140K miles -- with the original brakes still in service -- I sold the car. During the test drive the buyer (a woman) of course used very light braking and she noticed the pulsing and I gave her a slight adjustment in price to help cover the cost of new brakes.

In the case of your new car what could have happened is the car sits on the lot for some time. The brakes get wet from rain. And the brakes get wet as once in a while a team of car washers works through the lot rinsing/wiping down the cars.

So the brakes are very rusty. If someone takes the car out on a test drive and uses the brakes hard before applying the brakes lightly to scrub away the rust what happened with my VW Golf can and will happen, has probably happened with the Challenger brakes.

The VW dealer refused to replace the brake rotors or even resurface them under warranty. If the problem with your Challenger is the same as with my VW Golf you will probably run into the same resistance/refusal to address this.

So you are faced with living with the behavior which may not be acceptable and I can understand that or either replacing the rotors (either just the fronts and if this doesn't fix the problem the rears or all 4 rotors) or having the rotors resurfaced.

If (if) you are mechanically inclined you might be able to resurrect the brake rotors yourself by using some power sander tool with the proper abrasive pad/disc and scuffing up the brake rotor surfaces. You don't want to remove any metal to speak up you just want to well scuff the rotor surface evenly and equally on all rotor surfaces then after reassembling the brakes take the car out and do a brake bedding in operation. If you did the scuffing up right the pulsing should be gone.

While rare there might be a warped rotor. You can check for this by removing the wheels and checking the rotor radial and axial runout for excessive runout. I don't have the specs for this but the odds are only one rotor is "bad" so you can after having checked all 4 probably know which rotor is the bad one.

If you feel some vibration at speed not concurrent with braking this is either a wheel out of balance, a bent wheel/bad wheel, or a bad tire. Check all 4 wheels for any signs of tire (sidewall) or wheel damage. Check that the wheels do not show any signs of having lost a wheel weight. With the car in the air and safely supported spin the front wheels to "eyeball" for excessive tire (or wheel) runout/wobble. To check the rear wheels you might need an assistant in the car to use the engine to spin the rear wheels but they don't have to be spun very fast at all. Just with the engine idling and the transmission in 1st gear.
 

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If pad material left on the rotor can cause a pulsation of the brakes how in the world can you go about removing pad material with abrasives evenly and not cause additional uneven spots on the rotor surface. Is this material visible on the rotor. Asking because I have the issue for the second time in 35k miles and before replacing rotors I would like to give this a try. My thought was to use a 2" orbital air sander and hit the surfaces.


This still puzzles me however. Have owned several brands, sizes and types of vehicles through the years and have never had issues with brakes like this. Have never had to think about how I use my brakes. After a hard stop, consider not pressing the brakes to cause uneven pad material deposits on the rotors. Still can't help but think it's a design issue or I have just been lucky through the years...
 

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Make sure the wheels are torqued to spec, bed in the brakes. Usually that’ll solve your issue.
Every time you buy a new or used car and/or do a brake job the brakes need to be bedded in. Find an empty road/hwy, brake from 60 to 20 8 times and don’t touch the brake pedal for 3-4 minuets after the 8th time. I do it in the middle of the night on the fwy. Hardly any cars. They need to get really hot so you can get a nice layer of the pad material onto the rotors.
FYI, this is how I clean my rotors

 

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I have a slight vibration when braking at higher speeds as well. I believe it is just transfer from the MDS. I only feel the vibration when MDS is active, and I am at highway speeds(over 45-50mph). Turn on sport mode, no problem.
 

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If pad material left on the rotor can cause a pulsation of the brakes how in the world can you go about removing pad material with abrasives evenly and not cause additional uneven spots on the rotor surface. Is this material visible on the rotor. Asking because I have the issue for the second time in 35k miles and before replacing rotors I would like to give this a try. My thought was to use a 2" orbital air sander and hit the surfaces.


This still puzzles me however. Have owned several brands, sizes and types of vehicles through the years and have never had issues with brakes like this. Have never had to think about how I use my brakes. After a hard stop, consider not pressing the brakes to cause uneven pad material deposits on the rotors. Still can't help but think it's a design issue or I have just been lucky through the years...
You don't want to try to remove the material. It may not be that thick a layer. It may only show up as a few ten-thousandths of an inch thick.

You want to just rough up the rotor surfaces, all of them, and shoot for roughing them up all the same. You want to see some of the original rotor surface showing.

You want to rough up the rotor surfaces enough so in using the brakes but *avoiding* bringing the car to a stop (or you can create the problem again) has some chance of being able to remove the uneven pad material that is on the rotors.

From some mild braking if the pulsing is gone you can then advance to bedding in the brakes again. After a few hard brakes from say highway/freeway speed down to 30mph is sufficient. The rotors and pads already were bedded in and your roughing up the rotor surfaces doesn't change the fact the rotor and pads had already developed good surface contact with each other.

If after the agove if the pulsing is not gone there is no reason to continue. You need to be more aggressive with the sander or consider having the rotors machined if you have some place in town that'll do this.

As for how this happened, I have driven cars fitted with disc brakes for years without ever encountering this behavior. The VW Golf was my first time. I guess I have been lucky and like me I think you have been lucky.
 

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Discussion Starter #11
Brake Pulsation

Hi Guys

Thanks for the all the info. I will try Bedding the brakes and see what happens. I"ll let you Know
 

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Bedding the brakes cured a slight case of pedal pulsation on my 2015 SP. The bedding technique is important however, the pads and rotors need to get hot enough or it won’t work. I used the recommendations on this website: Bedding In Brake Rotors

Worked for me.



.
 

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This past Sunday I started out making sure the wheels were torqued properly, again. They were. Swapped out my winter setup for the stock setup and went for a drive to rule out the pulsation being an out of balance wheel which I have had balanced recently. Still there. Proceeded to take off the rotors and scour them down to bare metal. Didn't go crazy on them as suggested. Didn't see any un-uniform spots on the rotors like the pictures previously posted. Put everything back together and proceeded to go through the bedding process. I must say initially it felt like the brakes were better, and marginally they are. Not quite as much shimmy, but there is still an uneven kind of rolling when coming to a stop. A bit of hopping feeling felt throught the brake pedal. Not sure how to explain it I guess. Trying to decide if swapping out the pads and rotors with something not stock, stop tech, power stop etc will result in better longevity. But leaning towards putting together the Police package setup which it looks like I can do online for right about $500. Not mopar parts, but I think that's alright. Only concern is whether or not that setup will fit my 18" wheel setup as there if very little clearance from the wheel to the top of the caliper now. Guess I need to order one side and test fit and see.


Thanks for all the tips and info.
 

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Discussion Starter #15
Hi Guys
Follow up on my brake pulsation. I took the car back to the dealer for the second time, and this time they replaced the front rotors. No more pulsation.
Thanks for all comments
 

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Seemed pretty cut and dry. That is what it "usually" is. But usually not so soon....
 

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Thanks for the update. Replacement is the best solution.

Just a head's up. After washing the car remember to drive the car to use the brakes enough to get them hot enough to thoroughly dry the brake hardware. After washing, or if the car has been sitting out in the rain.

If the car has been sitting unused for a while arrange to use the brakes enough to scrub any rust away that might have formed on the rotors but avoid bringing the car to a stop from speed and leaving the hot pads in contact with the rotors.
 

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Decades ago you could turn rotors about twice before they were too thin to use.

Today they make the rotors on a lot of cars so thin to save weight they can't take a turn at all before they are below spec and will warp at the drop of a hat because they are so thin.

It's becoming common for a brake job to include new rotors.
 

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Decades ago you could turn rotors about twice before they were too thin to use.

Today they make the rotors on a lot of cars so thin to save weight they can't take a turn at all before they are below spec and will warp at the drop of a hat because they are so thin.

It's becoming common for a brake job to include new rotors.
It's SOP around here...
 
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