When taking off the front brake caliper for a rebuild, the master cylinder went low on brake fluid (didn't cap off the line as well as I thought).

After I topped off the MC with brake fluid a black plastic cap floated to the top of the MC. Anybody have any idea what the he11 this frigging thing is?!?!

Will try to post a pic in a minute.

thanks,
Colin


1999 Ford Contour SVT #900/2760 (SOLD) 2005 Mazda 6s 2003.5 Mazdaspeed Protege 1998 Ford Ranger 4x4