Melted brake pads after track day?

[halfwaytobedlam]

Hi all, had a track day over the weekend and saw that a hard, black substance that seems a little rubbery had formed on the brakes. Here are the details:

- The brake pads are Dixcel ES brake pads. I had not bedded them in and instead street drove with it for a couple months as the website suggested. Brake grease was placed on the pad surface contacting caliper.
- The track has lots of left turns and I braked from 170+ kmh to 80kmh on the first corner. I'm pretty new so i may have braked deep as I was turning
- The substance formed heavily on right front wheel, less on left front and none on rear
- Brakes were smoking lightly when i came into the pits
- Braking feel didn't change throughout the day as I continued lapping*. Car still tracked straight. I tried not to brake too hard and didn't observe any other substance buildup.
*after testing it in the skidpad

Trying to get an idea of what it might be before I send it to the mechanics to check it. Thanks in advance!

Attached are photos:

[EndlessAzure]

@halfwaytobedlam


I don't think that rubbery substance is brake pad. When pads melt, they smear onto your rotor and form marbling on the metal surface. Pads don't sling off like that; it's not possible (they aren't made of anything that would be rubbery)


If I had to guess, there are a few possible culprits:

1. You picked up some rubber marbles from your own wheels, other cars, or the track
2. Brake pad grease
3. Caliper pin grease

[psychore0]

My guess without seeing anything else is axle grease.

[halfwaytobedlam]

i suppose if grease from whereever gets ejected like that its probably a bad thing isnt it... but can grease harden up like that?

[WolfpackS2k]

It does look like axle grease a bit, and axle grease is pretty thick. Still, I'm not sure how axle grease would get flung onto the outside facing part of the brake rotor.

I second EndlessAzure's theory of it being rubber from track marbles. Especially since you reported that braking performance didn't change/deteriorate.

Also what tires are you running?

[Tcoat]

It is not grease. Grease at the temperatures reached would be runny and spread out on the rotor from rotation. No way it would be nice raised chunks.
It is rubber.

[NoHaveMSG]

100% not brake pad.

I had the same thing this last weekend. It was pieces of my fender liner.

[WolfpackS2k]

It's worth mentioning that on my previous car (Cayman) the axle grease overheated and flung out all over the place during a track event. The boots were intact - no issues. But apparently Porsche doesn't use a high temp axle grease on their sports cars...

Either way, none of it was on the brakes/any rotating assembly.

[NoHaveMSG]

Originally Posted by WolfpackS2k

It's worth mentioning that on my previous car (Cayman) the axle grease overheated and flung out all over the place during a track event. The boots were intact - no issues. But apparently Porsche doesn't use a high temp axle grease on their sports cars...

Either way, none of it was on the brakes/any rotating assembly.

As somebody who has smoked about 5 front hubs, I can say I have never seen any grease come out of any of them.

[halfwaytobedlam]

Originally Posted by NoHaveMSG

100% not brake pad.

I had the same thing this last weekend. It was pieces of my fender liner.

I think this may be it. my fender liners are pretty chewed up from the previous owner but I had a closer look on the inside and the hole was bigger and kind of melted. Seems theres a limit to how much zip ties can secure things

Thanks everyone for your input!

[bcj]

Originally Posted by NoHaveMSG

100% not brake pad.

I had the same thing this last weekend. It was pieces of my fender liner.

Originally Posted by halfwaytobedlam

I think this may be it. my fender liners are pretty chewed up from the previous owner but I had a closer look on the inside and the hole was bigger and kind of melted. Seems theres a limit to how much zip ties can secure things

Thanks everyone for your input!

Or pieces of other peoples fender liners and track boogers.
Do track owners have vacuum trucks, or are the renting orgs. responsible for cleaning up after themselves?

[NoHaveMSG]

Originally Posted by bcj

Or pieces of other peoples fender liners and track boogers.
Do track owners have vacuum trucks, or are the renting orgs. responsible for cleaning up after themselves?

It depends on the track and event organizer but typically they have a sweeper and will clean the track off from time to time. Like before the start of the day, if someone has an off, maybe at lunch. OPR was a big issue for me last weekend, it was pretty bad and they cleared the track off a lot but there were about 80+ cars running for times so there where a lot of marbles off line.