I was putting my rear wheel together and I noticed that my brake pads for some reason were really close to each other. I thought that I could push the piston back in. Being the noob that I am, I pulled the piston out thinking that I could just clean the piston with some brake cleaner and push them back in. Little did I know, there was brake fluid behind that and it splooged all over my hands. Well I put the piston back in but when I try to use the rear brake to see if it can put some pressure or move the piston out it didn't do anything. Looking at my rear brake fluid level, I need to refill it with DOT 4 brake fluid correct? Also, what else do I need to do to make my rear brake work?

Thanks for helpin guys! I'm still learning about my bike!

 

yeah fill up the fluid then you need to bleed the brake line, do this by opening the bleeder (i do believe it is located on the caliper) and slowly pressing down on the brake lever, just before you get to the bottom tighten the bleeder back up then release the brake lever, repeat this until you dont have any more air coming out when you bleed, only fluid

after your all bled out check to make sure your fluid level is still full

 

So I'm going to need to buy a bleeder. When you said, just before I get to the bottom, do you mean the rear brake lever? Repeat till I don't have air coming out, and than fill up with brake fluid. Is this all I need to do?

 

You dont need to buy a bleeder. Having two people will do the job.

make sure your reservoir is full, leave open.
pump the brake about 10 times.
Hold the pedal down and open the bleeder, air will come out as well as brake fluid, if you want less mess find a small clear hose to fit over the nipple.

DO NOT LET THE PEDAL COME BACK UP WHEN THE BLEEDER IS OPEN, this will allow air to go back in.
Close the nipple while the pedal is still depressed.
Check your fluid level, top off if necessary and repeat the above process until you fell the firmness and no bubble are coming out of the nipple.

 

think of it as a squirt bottle, when you push down, it expells whatever is in the tube, when you let off, it pulls whatever is at the open end back up the tube,

so if you have the bleeder open when you let off the brake, it will suck in air, when closed it will suck the brake fluid from the reservoir