Dodge Challenger Forum banner

Scat Pack rear brake issues ?

19K views 96 replies 21 participants last post by  Wisconsin Bob 
#1 ·
This is from a Charger forum & it looks like newer cars with 4-piston Brembos have pads that only sweep about 75% of the rotor's surface. Has anyone noticed this with newer Challengers?


It appears new OEM replacement pads are also smaller.
 
#2 ·
Rear pad PN has been the same for several MYs (68144223AC), the 'uneven' sweep should go away as the pads wear down beyond the chamfer (assuming there is one, have never taken brand new factory rear pads off myself).

That veh has 1500 miles and those are rear brakes so it'll likely take some time for them to fully seat.

PS - I should mention this ^ is my best guess just looking at the pics (and my own car), will look into it and update if I find anything relevant out there.
 
#3 ·
not with my '16 the pads sweep the face of the rotors all across
 
  • Like
Reactions: JavierA
#6 ·
I actually just cross posted onto the Charger forum. My car has the same weird partial rotor sweep that they're describing on their Charger Scats. I can't make sense of why Dodge would do this unless it's a straight up production error. Here's my cross post:

"My car does indeed have the same partial sweep rear rotor wear that you are outlining in this thread.

Here are my vehicle details:
a. 2019 Plum Crazy Scat Pack Challenger.
b. Mnfr Date 9/19
c. I purchase in Jan 2020
d. Current miles = approx 600"

986249
986250
986251
 
#7 ·
Just adding to this string I am sure the discussion will go on for a good long time. I have a 2019 SP WB currently has 700 miles on it and has the same wear pattern on the rear rotors. I have checked the new challengers at the local dealership and they have the same wear pattern. My car runs great stops really well with the 305s and I am not complaining.
Out of interest I checked the official Mopar parts site and found the hellcat brake upgrade package for challengers and while looking at the images provided on the website of the Brembo calipers and rotors I noticed even the new rotor parts only have a partial wear pattern.
I am not saying this is correct nor am I saying it is incorrect never the less the car rides and stops perfectly so I am going to keep on trucking just my 2 cents.
Don’t think I am pleading ignorance however in today’s automotive quality environment I am sure Dodge would have said something or issued a TSB if there were this many cars on the road with incorrect rear brake pads. And if they do in the future we will all get new pads and rotors. Sorry just me finding the positive out of the situation.
 
#11 ·
Enginerd I agree probably normal and I hate to get the thread tracking towards massive engineering calculation BUT, from a technical perspective the coefficient of friction is not impacted by the surface area covered by the brake pad friction material and hence the coefficient of friction is still good for the braking calculation. The braking torque capability however seems to be diminished slightly because the friction material does not use the last 10-12mm of the rotor which would create a larger braking torque moment (Torque = Clamping Force applied by the caliper x effective radius of the rotor in contact with the friction material)
The only downside I see here is the engineers are leaving some braking torque on the table and a weird wear pattern on the rear rotors, if they meet the CFR for all the braking tests then there would no design issue with the setup as is. The chamfer of the rear pads, as aggressive as they may seem, could have been done to correct the noise issues if you still meet the braking requirements you can keep increasing the chamfer on the pads until the noise goes away or customers stop complaining. There are many many threads about rear brake noise / squeal.
Hopefully we get an engineering type from Dodge to give us the full explanation.
 
#17 ·
I can confirm (officially) a chamfer was added to the top of the rear pads hence the new contact pattern (AC level pads). Not sure if it will go away as the pad wears but that is the new 'normal'.
 
#20 ·
Just a W.A.G. there are 2 different rear pads for the same caliper and rotor based on which front caliper and rotor you have. If you have the 6 piston 15.4" fronts (Hellcat, dynamics,widebodies) then you get the rear pads with more surface area. This is to balance out the larger fronts.
OR they determined that there was some other bias issue with too much rear braking and that was an easy fix.
FWIW, mine look like this.

986305
 
#23 · (Edited)
Just a W.A.G. there are 2 different rear pads for the same caliper and rotor based on which front caliper and rotor you have. If you have the 6 piston 15.4" fronts (Hellcat, dynamics,widebodies) then you get the rear pads with more surface area. This is to balance out the larger fronts.
OR they determined that there was some other bias issue with too much rear braking and that was an easy fix.
Rear pads had a J-chamfer added with the AC level release. This is official.
 
#26 ·
Check my logic:

  • If you have the new chamfered pads
  • Then you will have a ridge in your rotor over time
  • Which means, when you change brake pads - you must use the MOPAR pads
  • Because an aftermarket pad without the chamfer, will not seat on a rotor that has that narrow wear pattern and the associated ridge in face of the rotor

Is this accurate?
 
#27 ·
Check my logic:

  • If you have the new chamfered pads
  • Then you will have a ridge in your rotor over time
  • Which means, when you change brake pads - you must use the MOPAR pads
  • Because an aftermarket pad without the chamfer, will not seat on a rotor that has that narrow wear pattern and the associated ridge in face of the rotor
Is this accurate?
Great points...I've already asked, and from the standpoint of rust/appearance for those who eventually switch to AC from AB pads. When I get an answer I'll pass it along.
 
#30 ·
OK, so, it seems that they intentionally reduced the surface area. Next, I can only assume it is for a reason (not to save money, that would actually cost money to do). The only reason I can think of is to intentionally reduce rear braking, and the only reason for that is to eliminate rear lockup/loss of control.
OR, based on all of their commercials and other videos, it is to MAKE BURNOUTS EASIER!

Now, ignoring all of that, if they were going to reduce the surface area, why didn't they make the pad a diagonal/parallelogram type thing so it still hit all of the rotor surface, just not with as much pad. That would help cooling and appearance, I would ass-u-me.
Something like this.
986398
 
#31 ·
FCA ordered the pad revised for whatever reason, can't be for loss of control as you have ABS and ESC for that. For whoever wants the stock rear pads just order them direct from Brembo, otherwise the PowerStop Z23 or Track Day pads will do you fine.

Sent from my SM-N960U using Tapatalk
 
#32 ·
This was a rolling change implemented in MY19 depending on caliper PN so some 19s may have the older 'flat' (we'll call them) pads, whereas as other 19s+ will have the new chamfered AC pad.

I would suggest if you want the flat pad you get your hands on kit 68144223AB (or AA) while you can. Information will be forthcoming to dealerships to make them aware of the change.
 
  • Like
Reactions: MrF8Green
#33 ·
This was a rolling change implemented in MY19 depending on caliper PN so some 19s may have the older 'flat' (we'll call them) pads, whereas as other 19s+ will have the new chamfered AC pad.

I would suggest if you want the flat pad you get your hands on kit 68144223AB (or AA) while you can. Information will be forthcoming to dealerships to make them aware of the change.
I tried google, but couldn’t get clarity: what is the difference between ‘AB’ and ‘AA’
 
#35 ·
I noticed this wear pattern today on my 2019 SP. If one were to put on "full sweep" pads, wouldn't the abs take care of any braking issues? This seems very bizarre. They could have easily used a different compound instead of taking a quarter of the pad away and compelling you to buy new rotors at a pad change...
 
#36 ·
I noticed this wear pattern today on my 2019 SP. If one were to put on "full sweep" pads, wouldn't the abs take care of any braking issues? This seems very bizarre. They could have easily used a different compound instead of taking a quarter of the pad away and compelling you to buy new rotors at a pad change...
My main concern is getting boxed into buying the mopar pads at $200+ per axle vrs powerstop or others at $60 per axle because of a bonkers geometry choice on the pads.
(Or like you said - having to change the rotors as well)

Other than that - if the stopping force is the same as non chamfered, I’m ok with the weird pattern.

But I don’t like getting boxed into consumable parts that cost 3 times more, with no appreciable gain.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top