Stock Brembo's not working in the rain

[Stang70Fastback]

Originally Posted by kch

OP, everything I've read sounds 100% like the pads are either not bedded properly or (more likely) under temperature. I don't know how to fix this, besides either (1) riding the brakes a little (terrible solution); or (2) getting a more daily-friendly brake pad. I'm not sure what the OEM pads are on the PP, but if they come with a "hybrid" type pad like a DS2500, then you should ditch those and get some basic ceramics for street use.

That doesn't make much sense. You're saying its temperature-related, but then how does that jive with the fact that my DS2500s work fine when its 20 below zero here in Chicago, but suffer this issue when it's 90 degrees and raining.

I still think it has nothing to do with temperature/compound, and everything to do with water getting caught between the pads and the rotors. The brakes don't suddenly grab because very light brake application for 1 second caused them to warm up. They suddenly grab because it took a second for water to be removed, and for the pad to begin making contact with the brake rotor. At least that's what it feels like. It doesn't at all feel like the pad is suddenly coming up to temperature, and my experience with that pad in a wide range of temperatures here in Chicago pretty much disproves that theory anyway.

[Rabidpug]

2017 Brz with performance package here. I have noticed the same breaking issue. Basically I see it arise when I park outside and it rains heavily for a while. If when I drive later that day and do not break decently hard to clean off the rotors, once moving at a decent speed the break pedal becomes decently hard and applying the break feels like I’m using smooth glass as rotors. Full o shit pressure seems to get my car to stop, but scary. Not sure why this happens but only after a very heavy rain. I assumed rust build up, but the super firm pedal part I can’t explain.

[Swift]

I have a stock old acura legend as my daily, literally rusting apart. Same issue in the rain. I am running a single piston caliper up front, not a type 2 dual piston even. Metallic pads up front or all the way around. Napa gold. Not organic compound.


Point being, how many people race on a track in the rain?? If they made it like a normal street pad we would be complaining instead that there is dust everywhere and they only last x amount of miles. They tried to do a compromise or relied on Brembo's engineers and didn't validate themself. Look at how Toyota delayed the Supra more because they were not totally satisfied with (waterpump???) reliability. The part is actually changed but not on the BMW.



Swap out the pads to a more street one and report back. Answers help a forum!


Ps- Imagine your same issues with a cold temp automatic where torque convertor is staying locked up I think. Literally trying to hold it back from pushing me through the first stop sign some days. Now that can be scary.

[BRZnut]

The last time I had a car that did not stop in the rain was when Drums were on all 4 wheels!