AMG GTR brakes failure - Mercedes refuses warranty




The ABS traction control is just super aggressive on the CCBs. It works amazingly well with the 720 hp AWD of the wagon but it does cook the brakes and fluid going uphill in a 4,700 lb. wagon..
I guess I should stop videotaping Ducatis behind me in the canyons..

On my first test drive [50mi.] in a 2018 CCB equipped wagon through the canyons the brake pedal developed an inch extra travel due to cooked brake fluid on the uphill and downhill section...
Try doing the CCB bedding procedure recommended and tell me the pedal doesn't go soft due to the excessive heat buildup..
Traction control works the brakes hard on the uphill without you even knowing it, until you get out and smell them cooking while you scratch your head wondering when and where you were heavy on the slow pedal.
Some people drive and some people think they can drive. You are free to follow me through the canyons anytime as long as you never cross the centerline and let's see how well your brakes hold up in my world.
Castrol SRF fluid Dry Boiling Point = 312° C (594° F); Wet Boiling Point = 270° C (518° F); "DOT4"
Now 500*C brake temps are more than 312*C the dry boiling point of Castrol SRF.
With little to no cooling airflow to our brake systems it's not long before fluids begin to cook due to the traction control constantly correcting yaw..
Last edited by ronin amg; Jan 14, 2019 at 05:37 PM.
Fresh Castrol SFR fluid is almost good enough to do the job but still lacking the durability to go for more than a few months of canyon driving..
I've talked to real Mercedes racers about the fluid issue before and after I did the flush and they all said it was the traction control and a lack of cool air directed to the brakes..
Again, never a soft pedal in my 3,600 lb GTS with steel brakes and OEM Mercedes dot4. But the heavy 4,700 lb. wagon is another story even with it's CCB and Castrol SFR fluid...
On my first test drive [50mi.] in a 2018 CCB equipped wagon through the canyons the brake pedal developed an inch extra travel due to cooked brake fluid on the uphill and downhill section...
Try doing the CCB bedding procedure recommended and tell me the pedal doesn't go soft due to the excessive heat buildup..
Traction control works the brakes hard on the uphill without you even knowing it, until you get out and smell them cooking while you scratch your head wondering when and where you were heavy on the slow pedal.
Some people drive and some people think they can drive. You are free to follow me through the canyons anytime as long as you never cross the centerline and let's see how well your brakes hold up in my world.
The pedal does go ‘soft’ during a true CCB ‘burnishing’ procedure, but that has nothing to do with the brake fluid, rather you are conditioning and ‘out-gassing’ the pads themselves, that’s what causes the soft pedal. It’s pad fade, not fluid fade. Once this has been done correctly this should not happen again as the pads are then seasoned.
What you are experiencing during your canyon drives is intriguing as you know as well as I do that no matter how fast a person drives in the ‘canyons’, or anywhere else on a street, you can never expose a vehicle to the same braking forces as you routinely see on a road course; it just doesn’t happen. And SRF does not ‘cook’ on a road course. I’m wondering if your ESC isn’t constantly kicking in, and over-heating the rear pads in particular, giving you a major issue with pad fade even though you’ve tried conditioning them; this made worse by the fact that the OEM pad is extremely street oriented and can’t withstand the high temps caused by prolonged brake application by the ESC as well as of course the weight of the car.
I would try this: drive your normal route but with ESC ‘Off’, and see if you still experience a soft brake pedal. To be safe, dial the velocity down somewhat of course. I suspect you might notice a lot less brake pedal fade. If that doesn’t work, consider upgrading to the Pagid RSC1 pads.
But BenzGTR is correct: unless you’ve got air in the brake system which can and does easily happen even when a fluid flush is done under pressure at a dealership; SRF just won’t ‘boil’.
Bish
The Best of Mercedes & AMG
The pedal does go ‘soft’ during a true CCB ‘burnishing’ procedure, but that has nothing to do with the brake fluid, rather you are conditioning and ‘out-gassing’ the pads themselves, that’s what causes the soft pedal. It’s pad fade, not fluid fade. Once this has been done correctly this should not happen again as the pads are then seasoned.
What you are experiencing during your canyon drives is intriguing as you know as well as I do that no matter how fast a person drives in the ‘canyons’, or anywhere else on a street, you can never expose a vehicle to the same braking forces as you routinely see on a road course; it just doesn’t happen. And SRF does not ‘cook’ on a road course. I’m wondering if your ESC isn’t constantly kicking in, and over-heating the rear pads in particular, giving you a major issue with pad fade even though you’ve tried conditioning them; this made worse by the fact that the OEM pad is extremely street oriented and can’t withstand the high temps caused by prolonged brake application by the ESC as well as of course the weight of the car.
I would try this: drive your normal route but with ESC ‘Off’, and see if you still experience a soft brake pedal. To be safe, dial the velocity down somewhat of course. I suspect you might notice a lot less brake pedal fade. If that doesn’t work, consider upgrading to the Pagid RSC1 pads.
But BenzGTR is correct: unless you’ve got air in the brake system which can and does easily happen even when a fluid flush is done under pressure at a dealership; SRF just won’t ‘boil’.
Bish
The wagon is faster and weighs 1,000 lbs more than the GTS and that extra weight is the real problem with zero brake cooling... As I've been saying I get a soft pedal going up hill using the brakes lightly and traction control on. I've been temped to turn it off and do a complete run but all ya get then is a runaway Rhino with 720hp, so I leave it on...
Who wants to drive in a straight line anyway when ya got *****in canyon roads to play on...
If you are not a hard canyon driver and only stick to a road course you are not getting the entire driving dynamic picture I'm trying to point out.
It is nothing like a road course.
It's all about being smooth and quick. It's never about late braking at high speed into a blind corner because that will just get you dead.
I pride myself on being smooth in the canyons and saving my brakes for the downhill ride home.
We need to find a proper brake cooling option for both the GTS and e63s wagons out there..
Ray, I’m assuming you mean ‘bleed’, not ‘flush’; yes?
If a person has their brake system flushed, (where the brake fluid is completely exchanged), too often, they are increasing the odds of getting air in the system; having a bleeder damaged, etc. IMHO, instead of just exchanging the fluid annually or when the manufacturer states to do so. 18 months for Castrol SRF.
Ray, I’m assuming you mean ‘bleed’, not ‘flush’; yes?
If a person has their brake system flushed, (where the brake fluid is completely exchanged), too often, they are increasing the odds of getting air in the system; having a bleeder damaged, etc. IMHO, instead of just exchanging the fluid annually or when the manufacturer states to do so. 18 months for Castrol SRF.
I don’t know why I keep calling it flush.
I've designed a duct for our front brakes. The one in the photo is for the left side. It mounts to the lower a-arm and routes air to the opening between the knuckle and the brake caliper. This will feed the rotor as well as cool the caliper. The design is 3d printed in polypropylene which is the same plastic that other manufacturers use for their ducts. It provides temperature resistance and is tough so can it be deformed without breakage.
I've designed a duct for our front brakes. The one in the photo is for the left side. It mounts to the lower a-arm and routes air to the opening between the knuckle and the brake caliper. This will feed the rotor as well as cool the caliper. The design is 3d printed in polypropylene which is the same plastic that other manufacturers use for their ducts. It provides temperature resistance and is tough so can it be deformed without breakage.
When will these be available for purchase?
Any thoughts on ducts for the rear wheels, as for those people who run run ESP ‘On’ the rear brakes can get fried.
Bish
You can see from the first photo how the duct mounts to the lower a-arm. The second photo with the caliper has the left knuckle turned fully to the right to show the exit of the duct. The third photo shows the left wheel at full lock to the right to illustrate the clearance for the duct. The final photo shows the OEM channel in the undertray. The duct is designed to be in line with that channel to route the air between the caliper and the knuckle.
The rear knuckle has been scanned, I'll be working on the rear brake duct next.





