So I unfortunately got caught out in some really bad weather yesterday. It snowed with ice here around 5 inches and it accumulated very quickly. So now today it's back to being 40 and sunny (roads are clear now), but my TTS doesn't stop as well as before.

It still stops well, but it doesn't have that like neck snapping stopping power before the snow. I noticed when I got home finally my front wheels inside the rim were completely covered with snow including my calipers. The rotors were clean however. Also the rear rims and rotors were completely clean. When I reverse and stop, the braking is sudden. But going forward and trying to stop I have to press the pedal like 1/4 of the way down to get any real stopping power.

Is this something that I should be concerned about now? I don't think there is like a rock or anything in-between the rotor and pad, the pedal feel from the brake is completely clean. I don't feel any gravely feeling like something is stuck in-between there.

In other news though my car did fantastic in the snow. Everyone in SUVs, trucks, and sedans were getting stuck, but the TTS just plowed on through .

EDIT: Some google searching found on the BMW forum that their ceramics in heavy rain causes a diminish in performance which apparently is normal. I'm wondering if maybe cause the rotors were wet or something I lost some braking power.

 

Not sure about the PCCBs but did you have snow tires on your TTS? Just curious.

 

Of course. Otherwise I would have been screwed.

It's interesting. Though I'm wondering if this is from being wet or something. I would characterize it as my breaking power is maybe 20-30% less. I haven't driven my car since this morning though so I'll see how it is tomorrow. I'll probably call my dealer. I don't think though its caused from it being wet.

When my rotors are wet when I pull out of the car wash, I literally have zero braking. My breaking is maybe 10% until they dry real quick.

 

178 views and one comment? Makes me think I'm the only one who has driven a TTS in snow or rain apparently.

 

Go for a spirited drive and they should be normal after heating up. No long term issues. Prob some salt dust.

 

heat them up and will work fine again

 

I've never driven my car in snow or rain but have experienced what you are describing when the brakes are really cold. After heating them up a bit as prodigymb said, they "bite" again. I definitely have decreased braking when they are real cold.

 

Well here is the first time (and last time) I drove my car in the snow lol. I have always been able to avoid it, except this day. It came out of nowhere and accumulated like instantly.

I think salt is also a culprit here. I'm taking it to get washed tomorrow. Since it's in the 20s today and the water will just freeze on the car like last time I tried. Tomorrow will be high 30s.

 

In Colorado where I live, they treat the roads with Magnesium Chloride instead of traditional salt. There is a binding agent in the Mag Chloride that sticks to brake surfaces and it definitely impacts braking performance. I notice it more with my PCCBs than I did with the steel rotors on my C4S. It will wear off with driving, or you can take it to your local carwash and rinse it off with the high-pressure wand.

Could this be your issue?

 

You know what, it could be. I'll see what happens after I get it washed tomorrow.

 

I've noticed that my PCCBs make a grinding noise when stopping at slow speed before I rinse off the magnesium chloride. Did you hear anything like that?

 

No grinding. We'll see tomorrow. They are better today.

 

Maybe "light scraping" was a better way to describe it. In any case, I hope a good rinse helps your brakes.

 

Any update?