Front Brake Reservoir Gunk

[Eagle6]

Fitting an extended brake line this morning.
Used a big syringe to remove the majority of fluid from reservoir and the photo shows whats in the bottom. Any ideas??

[mogu83]

At this point all you can do is clean everything, install the new line, flush the entire system and keep an eye on it.
IMHO

[Eagle6]

The bike has only done 2,759 miles and had a brake fluid change at 1,650 in 2014.

[mogu83]

The bike has only done 2,759 miles and had a brake fluid change at 1,650 in 2014.

Interesting - but right now you can only go by what your eyes see. Lots of things could have caused what looks like some sort of contamination, but the logical course is to clean everything and start over.

[GTS29640]

I've never seen anything like that before with brake fluid. I agree a thorough flush is in order. It will be interesting to see what flushes out and hopefully none of that white gunk will have migrated thru the system.

Did the brakes seem to work OK before you started your brake line project? I noticed you posted a few photos of your bike a few days ago and the color of the fluid looked darker than anything I've seen before, not the typical pale yellow or light amber.

[Eagle6]

I've spent some time today flushing through the fluid. Surprisingly I've not seen anything come through the system and the lever is firm.
I've seen some bikes that have a plastic/polystyrene 'float' in the reservoir and my first thought was that there was originally one in the reservoir and it had dissolved but I've found no evidence that one was fired to this model.

It was a soft substance and I removed the whole brake assembly and cleaned it out with an artist's brush. Everything seems good so fingers crossed.

[deilenberger]

My '12 has an open-foam anti-froth thing in the brake reservoir. Came on the bike. So far it hasn't dissolved.. wonder if that's the remains of one, but also wonder what caused it to melt down like that. FWIW - I broke the original master cylinder (tip-over into a vice whilst doing a front tire swap) - and bought a new one ($500.. dammit..) and the new one didn't come with the foam thingie, so I moved it over to the new one from the old one. Still looks good (around 40,000 miles on the bike..)