Front versus rear brake dust & heat
Thread Starter
Super Member
Joined: Dec 2005
Posts: 785
Likes: 113
From: Scottsdale, Arizona
2020 S63 Coupe, 2006 Hummer H1 Alpha, 2018 McLaren 720S, 2022 Porsche 911 TurboS, 2022 Tesla Model X
Front versus rear brake dust & heat
I've noticed my S63 coupe rear brakes got considerably hotter than the front after regular driving around town. I am also seeing more dust on the rears than the fronts. This is opposite what I always experienced with the CLS63S, so wanted to know if it is normal or there is a problem with the front brakes that is overloading the rears ?
My typical daily driving around here is 35-65mph with traffic lights every 1/2 mi or so. I don't drive aggressively most days because of frequent stops and lots of slow moving vehicles. I have not yet checked temps after fast freeway driving, or aggressive street driving with sudden tops but will do so.
I did have my calipers painted about six months ago, and OEM pads were replaced with Porterfield R4-S at that time. I didn't bother to check front versus rear dust and temps before the new pads were installed. The R4-S are certainly not dust-free but definitely much less than the factory pads, it takes a couple weeks for the wheels to get a coating of brown dust versus a few days with the OEM pads. There is definitely now more dust accumulating on the rears than the fronts. I have not perceived any significant change in brake feel or stopping ability.
My next regular service is not due until June, but if something is amiss I will obviously bring it in earlier to get them checked.
My typical daily driving around here is 35-65mph with traffic lights every 1/2 mi or so. I don't drive aggressively most days because of frequent stops and lots of slow moving vehicles. I have not yet checked temps after fast freeway driving, or aggressive street driving with sudden tops but will do so.
I did have my calipers painted about six months ago, and OEM pads were replaced with Porterfield R4-S at that time. I didn't bother to check front versus rear dust and temps before the new pads were installed. The R4-S are certainly not dust-free but definitely much less than the factory pads, it takes a couple weeks for the wheels to get a coating of brown dust versus a few days with the OEM pads. There is definitely now more dust accumulating on the rears than the fronts. I have not perceived any significant change in brake feel or stopping ability.
My next regular service is not due until June, but if something is amiss I will obviously bring it in earlier to get them checked.
MBWorld Fanatic!
Joined: Jul 2014
Posts: 1,270
Likes: 160
From: UNKNOWN
NB8 PARACHUTE
`
Are your front rotors vented
and are the rear rotors solid
If they are solid they will
be hotter
It should have vented rotors
front and rear
Thank-You
D.B.
`
Are your front rotors vented
and are the rear rotors solid
If they are solid they will
be hotter
It should have vented rotors
front and rear
Thank-You
D.B.
`
Last edited by COOPERDB; Feb 21, 2017 at 10:01 PM.
Thread Starter
Super Member
Joined: Dec 2005
Posts: 785
Likes: 113
From: Scottsdale, Arizona
2020 S63 Coupe, 2006 Hummer H1 Alpha, 2018 McLaren 720S, 2022 Porsche 911 TurboS, 2022 Tesla Model X
D.B. - yes slotted and vented front and rear
I think your PM probably explains it - EBD system probably using more force on the rear breaks for maximum stability under normal light breaking. I would expect an error light or code too, if the braking system had some malfunction. I wouldn't have ever thought twice about it, except it is the exact opposite of what I experienced with the CLS63S which had the identical drivetrain, but smaller wheels/tires and about 400 fewer pounds.
Rear pads definitely will wear out quicker based on the heat and dust I see, we'll see how they are wearing at the next service interval.
I think your PM probably explains it - EBD system probably using more force on the rear breaks for maximum stability under normal light breaking. I would expect an error light or code too, if the braking system had some malfunction. I wouldn't have ever thought twice about it, except it is the exact opposite of what I experienced with the CLS63S which had the identical drivetrain, but smaller wheels/tires and about 400 fewer pounds.
Rear pads definitely will wear out quicker based on the heat and dust I see, we'll see how they are wearing at the next service interval.
MBWorld Fanatic!
Joined: Jul 2014
Posts: 1,270
Likes: 160
From: UNKNOWN
NB8 PARACHUTE
`
Not knowing what the previous owner
did service wise hence the rotor question
The EBD system is harsh on the rear brakes
(regular brakes/pads) on the S63/65 coupe
CCB's are the solution - you know that
You also know how rare CCB's are
Please update pad wear as time permits
Thank-You
D.B.
`
Not knowing what the previous owner
did service wise hence the rotor question
The EBD system is harsh on the rear brakes
(regular brakes/pads) on the S63/65 coupe
CCB's are the solution - you know that
You also know how rare CCB's are
Please update pad wear as time permits
Thank-You
D.B.
`
Last edited by COOPERDB; Feb 22, 2017 at 02:40 AM.
