I replaced my brake pads today, and did a quick, funnel only bleed in case any air had made it in.
When I pumped the lever I could see an exchange of mineral oil and the oil coming out of the levers (both the same) was a cloudy black which I've never had before.
Is this a sign of imminent failure? The brakes have been working fine and still seem to be. Is it safe to ride until I can do a full bleed or has something started to break down?
I've got ancient SLX levers paired with newer SLX callipers. Hoping that I don't need new brakes!
I thought all break fluid was black? It certainly is by the time I'm done with it.
Shimano mineral oil is pink.
He's trying to be funny.
It's normal for your existing oil to come out murky grey, will be quite safe to ride until you can do a proper bottom-up bleed.
Cheers! I'm clearly a bit slow today.
Mine is always a bit black, looks like a suspension of particulate.
I've always assumed it's crud that's been cleaned off the pistons/got passed the seals during operation.
I tend to keep pumping new fluid through the brake until it's clean-ish coming into the cup.
I've seen a hypothesis that it's some sort of dye/colouring from the seals. It doesn't appear to affect operation.