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Challenger SRT Hellcat
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Discussion Starter · #1 ·
My rotors were replaced under warranty at 3,000 kms for pulsing/grabbing at speed. I carefully (not aggressively) bedded the new rotors and they were fine after that.

Well, 19,000 kms later it's happening again. Realistically, it started earlier but I HAVE to do something about it now.
Is it possible to reverse the bedding process by removing the rotors and using a brake cleaner Scotchbrite pad on the rotor surface?
Rotors are not scored, lots of pad (OE) left, street driving only.

The rotors LOOK new. I don't hammer the brakes on a regular basis, and after the warranty replacement I have been careful about overheating the brakes.
Damn.
Can I salvage my OE setup?

2017 6 speed Hellcat.
 

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2020 Challenger Hellcat Redeye Wide Body
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12,744 Posts
Do you torque your lugnuts after removing/re-installing the wheels?
 

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Challenger SRT Hellcat
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597 Posts
Discussion Starter · #5 ·
Never an impact- by hand with an X wrench (for removal and for install) then click type torque wrench.
Tension on the torque wrench released immediately after.

Can I somehow clean off the rotors without damaging them? I plan on removing and reinstalling everything. Can I clean off the pad material off the rotors with brake cleaner and then bed them again as if new?
 

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Charger SRT Hellcat
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1,566 Posts
Never an impact- by hand with an X wrench (for removal and for install) then click type torque wrench.
Tension on the torque wrench released immediately after.

Can I somehow clean off the rotors without damaging them? I plan on removing and reinstalling everything. Can I clean off the pad material off the rotors with brake cleaner and then bed them again as if new?
Try brake clean & let it soak a bit.

Also recommend to stop the Bedding stuff. It's not necessary with modern friction materials.

What pads are you using?

Check the torque on the rotor ring nuts?
 

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2019 Challenger Hellcat Widebody (destroyer grey)
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648 Posts
I'm wondering if you have faulty calipers, causing some unneeded clamping onto the rotors than is designed while not applying the brakes. In other words, the calipers may be sticking some.
 

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Challenger SRT Hellcat
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597 Posts
Discussion Starter · #8 ·
Ok, I'll try cleaning everything thoroughly and just drive normally.

I wondered about the calipers too. I'm going to check the pistons thoroughly.
I have done a brake flush myself and everything went fine. I siphoned from BOTH breeders per caliper too.

I am perplexed at this happening again. Literally fewer than 15,000 MILES on the car, street driven.
 

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Charger SRT Hellcat
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1,566 Posts
Stock Brembo pads.
Stock rotors.
Make sure the front hub flange, rotor plate & the wheel flange is clean.

You may need to dial indicate the rotors to see if there is any warping or runout after torquing the rotor onto the hub flange w/o the wheel.

FWIW, am not a fan of siphon/vacuum bleeding when there is an ABS System. It's either 2-man or pressure bleeding.
 

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Discussion Starter · #13 ·
Yeah, I'll give all surfaces the once-over while it's apart. I have the dreaded click-click sound when turning the wheels again, too.
Last time I cleaned the wheel mating surface on the rim and hub and all was quiet again. Could this be related?

Regarding the siphon method, I was very diligent in preventing any chance of air entering the system either through the reservoir OR the breeders. I pulled almost a quart through. Pedal is FIRM.
 

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'23 Redeye Jailbreak
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5,010 Posts
My rotors were replaced under warranty at 3,000 kms for pulsing/grabbing at speed. I carefully (not aggressively) bedded the new rotors and they were fine after that.

Well, 19,000 kms later it's happening again. Realistically, it started earlier but I HAVE to do something about it now.
Is it possible to reverse the bedding process by removing the rotors and using a brake cleaner Scotchbrite pad on the rotor surface?
Rotors are not scored, lots of pad (OE) left, street driving only.

The rotors LOOK new. I don't hammer the brakes on a regular basis, and after the warranty replacement I have been careful about overheating the brakes.
Damn.
Can I salvage my OE setup?

2017 6 speed Hellcat.
Sounds like the ABS controller/pump doing something odd.
 

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Charger SRT Hellcat
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Stock Brembo pads.
Stock rotors.
Make sure the master cylinder reservoir is not overfilled. There should be 1/4" to 3/8" air gap between the top of the fluid level and the top of the reservoir just below the cap threads. If there is no expansion room, brakes can be applied as the fluid heats up. It only takes 1/2 (.5) PSI to apply a caliper.
 

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2015 Charger SRT Hellcat
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4,082 Posts
"IF", it is uneven pad deposits like pulsing normally is, you need to use red garnet paper (no metallic particles), to get the deposits off. Like was said, I never heard of stock Brembo pads and rotors doing anything bad; other than dust! Add a picture of the rotors.
 

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2020 Challenger Hellraisin Scat Pack.
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3,225 Posts
My rotors were replaced under warranty at 3,000 kms for pulsing/grabbing at speed. I carefully (not aggressively) bedded the new rotors and they were fine after that.

Well, 19,000 kms later it's happening again. Realistically, it started earlier but I HAVE to do something about it now.
Is it possible to reverse the bedding process by removing the rotors and using a brake cleaner Scotchbrite pad on the rotor surface?
Rotors are not scored, lots of pad (OE) left, street driving only.

The rotors LOOK new. I don't hammer the brakes on a regular basis, and after the warranty replacement I have been careful about overheating the brakes.
Damn.
Can I salvage my OE setup?

2017 6 speed Hellcat.
While my experience is actual brake rotor warping is rare you need to check the radial/axial run out of all the rotors. If there is any warp replacement is really the only solution.

My only experience with pulsing brakes arose from an emergency stop with rusty rotors. I made the mistake of after washing the car parking it instead of driving it to dry the brakes. When I took the car out a day or two later the brakes were rusted up enough they let go with a "pop" as moved the car on the driveway.

I didn't think to perform a mini bed in procedure to clear the rust. So after the emergency stop the brakes pulsed upon light application. I managed to change my braking style to avoid this pulsing and put around 150K miles on the brakes.

If the pulsing is from uneven pad material deposition you can possibly remove the pad material -- scuff up the rotor surface enough that under bedding in braking the pads will be able to remove the rest of the pad material -- by manually sanding the rotor surfaces.

For cast iron you want to use aluminum oxide abrasive. You don't want to try to actually remove any substantial amount of metal. You'll just make the rotor surface "wavy" and compound the pulsing. You just want to abrade the surface and enough the pads when applied can (technical term) glom on to any pad material on the rotors and remove it. Hopefully.

Use a good mask to avoid breathing in the cast iron or abrasive dust. Be sure to thoroughly clean the rotors with a good sprary of brake cleaner to remove any dust, oil, etc.

You are facing a good amount of work even with a power (air power or electric power) die grinder fitted with the proper abrasive disc and you may not be successful. So either resurfacing the rotors -- which brings with it risks -- or replacement is the solution.
 

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2019 Challenger Hellcat Widebody (destroyer grey)
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648 Posts
Does anybody that drives the vehicle sit with full pressure on the brake pedal after a stop? Especially a hard stop such as after a freeway exit and sitting at a stop light?
Always let up after stopping and I leave enough room to creep forward when coming to stop.
Exactly what I have always done, and also stressed this to my wife as well after she warped the front rotors on our MDX. You don't want to be compressing hard on a hot rotor at a stop.
 
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