Originally Posted by Alex-r-1

Today I bought a new Bleeder Screws (my screw was rusted inside) on my dealer. Included was the instruction Brembo how to replace Bleeder Screws and was table with torque settings.

Originally Posted by Diabolis

AFAIK it's a pair so it does one caliper.

Originally Posted by Diabolis

AFAIK it's just a Brembo bleeder screw that is used on gazillions of different cars and calipers (M10x1.0 IIRC). The W204 C63 uses the same one on all four corners (two each on the fronts, one on the rears). If Mercedes is now selling them as individual items and the price doesn't reflect that, for as long as they are the genuine article I'd buy them from anywhere.

Originally Posted by BLKROKT

I bought a bag of them when I rebuilt my calipers last year. Will check what vendor I got them from, and if I have any left I’ll send you some. You need all 6?

Originally Posted by Diabolis

Nope - I haven't managed to boil it yet under heavy track use (continuous ~1.5 hour sessions - basically a full tank of gas), at a fast track with heavy braking zones where you repeatedly hit 230+ km/h before you have to slam on the brakes to slow down to 80 km/h to make the next corner. I cooked my OEM brake pads, but the fluid was not an issue at all. The brake pedal didn't get even slightly spongy with fresh OEM MB fluid.

You do need to completely flush the brake fluid every two years even for street use (and at least once or twice a year if you're going to track it, and for good measure I always bleed a few CCs - an ounce or two - from each caliper after every track day in case there's any burnt or boiled fluid, but the last two times I went out the with the C63 I didn't see a single bubble, it was perfectly clear and didn't smell burnt at all, so even the little bit of fluid that was in the caliper itself took the heat with no ill effects).

As far as braking goes, IMHO the weakest link for track use are the OEM brake pads. They actually perform more than adequately even on the track, and I got only a *slight* amount of fade (maybe 5-10% at the most) after about ~15 laps or so (again, not fluid-related - the brake pedal feel was constant), but you will cook the pads and they will stink afterwards and have that 5-10% less bite for the rest of their life.

All of this assumes that you have the retrofit track cooling package installed of course, as your car will go into limp mode because of overheated oil *way* before you manage to get anywhere near the limit of the OEM brakes.

Originally Posted by 2020C63s

i agree i got a 2020 c63s coupe and i cooked my oem break pads in one track day which were fairly id say at 50%! Got some Pagid Yellows break pads which are amazing but on the 50th lap my oem break fluid boiled up ! Although i didnt have the fluid changed prior to going , im looking at Castrol SRF for the next track day… any experience with this fluid?

Originally Posted by Diabolis

In terms of boiling point, Castrol SRF is the best there is, period. It is twice the price of anything else on the market and what I use in both of my race cars, but how friendly or compatible it is with the ABS pump in the C63 is anyone's guess. It is more viscous than the OEM fluid, but I have no data how this may affect the ABS pump operation or longevity.

And, FWIW, absorbed moisture from the air is the biggest problem on street vehicles, and fresh OEM fluid always beats the best old fluid. On the race cars I bleed the brakes at the end of every track / race day, and flush it completely after two race weekends (so it is basically never older than a month). On the C63 I would flush the fluid after two track weekends, and that was with the MB OEM fluid.

Originally Posted by Diabolis

Not really.

The primary issue with using any aftermarket brake fluid is that the MB fluid is generally much thinner. The hydraulic pressure inside the ABS pump is in excess of 3000 psi, and if the brake fluid doesn't have the correct viscosity, it can start to cavitate when it is rapidly forced through the pump or valves, which happens when ABS or TC / ESP (on your 2020) engages and the system brakes an individual wheel to stabilize the car. Cavitation produces gas bubbles - which is the LAST thing you want in your brake system. In other words, using that SRF (or anything else) on a car with ABS is great for as long as you never engage ABS, and on a car that has the TC / ESP that yours does, for as long as you never overcook it going into a corner. In other words, I'd most definitely think twice about putting in anything other than MB 331.0 brake fluid. Besides, the MB fluid is actually very good... it has a (dry) boiling point of at least 271C or 520F. That's up there with most performance brake fluids.

How old was your brake fluid when you did the track day? I suspect that it may have boiled because it was old and had absorbed plenty of moisture, not because the fluid is not good enough.

Originally Posted by Diabolis

If the pedal was hard but you had no brakes, that's not a result of boiling the brake fluid - that's pad fade which happens when you overheat the pads and their friction coefficient drops (the pad material is basically starting to burn or melt). Common with OEM pads. If the pedal went to the floor, that's because you boiled the fluid and ended up with gas bubbles in the brake lines, which unlike hydraulic (brake) fluid, is very compressible.

The Mercedes brake fluid properties are from the PDF that you can get from BEVO... they're hidden about halfway down in the MSDS document (which is in German). As for the wet boiling point, I don't recall what it is but it generally it depends on how much moisture the fluid has soaked up - and should for all intents and purposes be a useless data point. Most clubs require that you flush the brake fluid no more than 60 days before your track day for precisely this reason.