well i was at my grandparents the other day and my grandpa looks at my bike and goes is that a brake fluid reservoir? I said yeah that's just for the rear brake.

he goes, well there is no fluid in there!?!?! hahah well turns out there it was empty and it makes sense because when i was changing the sprockets i couldn't get my rear brake to stop and hold the wheel to tighten some of the bolts.

I haven't found a leak yet, but i did notice a silverish type fluid/stain on the right side of my bike underneath the reservoir, but i don't think brake fluid is silver? i just used a heavy duty engine degreaser and spray it all over the rear of the bike so i'm assuming the silver stuff is from that but i don't know where the rear brake leaked from.

And once i put it more fluid i'm going to need to bleed them right?

 

If there's no fluid, the entire rear brake system is full of air. Including the master cylinder. If you don't have one, I recommend getting a vacuum pump from the local auto parts store to help. It'll be difficult to bleed it without one.

 

Fill it up, bleed it, then watch for leaks.

 

The rear brake is easy to bleed, just need a clear tube over the bleed nipples and into an empty bottle and some brake fluid. The hard part, or rather the part people fail miserably at is getting the initial lever pressure, once the MC is pushing fluid it is easy, if you don't bleed the MC first then you are just squashing air inside the MC.

Fill up the res and do not let it go empty at any point. Best to start by bleeding it at the MC banjo first to get the MC pumping fluid, i.e. crack the banjo open and pump the lever a few times to get some pressure and fluid movement (use a rag to mop up spills), then tighten it up and bleed it at the caliper (pump, crack open the nipple for a split second then retighten - repeat). Do it at the caliper until the clear plastic line is not pumping out any bubbles. If the lever is still soft then bleed at the MC banjo again, and bleed at the caliper banjo before doing a few bleeds at the nipple.


Sounds tricky but it is not, you'll quickly get the feel for it.