Yellow sponge in master cylinder

[RS530]

[Capnrip]

The last time I did a brake flush I changed mine because it looked like crap. Don't know that it had ever been changed, I bought the bike used. I guess the thing to think about is if it does start to deteriorate do you want that crap going through your brake system? Yeah, I get the fact that it's $25 for a sponge, but it's a BMW sponge! Don't know if it's made of upsidaisium, but in the world of BMW parts $25 is a cheap one. Amortized that's 12.50 a year. They want $30+ for a rebuild kit for the TPMS which is a little rubber gasket and a valve stem. Probably about $1.98 worth of stuff. So back to your problem, I'd open it up, if it looked like new, I'd move on. Then you have to think what's it going to look like two years from now.

[RS530]

I have no idea if it would ever deteriorate, that was just me speculating. But believe me I understand where your coming from. Thanks

[RS530]

Well I just went and bought the sponge $26.70 for a 10 cent piece of sponge, give me a break I feel like I just got screwed royally