The red lines that are visible on the pads are the wear limits. If your pad is approaching the red line, not a bad idea to replace it. Also, the bolt with the spring on it that adjusts the caliper position with respect to the disk. Adjust that bolt until the right brake pad just touches the brake disc. Back it off until it doesn't touch the disc at all, then back it out one half of one turn more.

Check the rear brake arm pointer. It should be within limits marked on the side of the rear brake housing, and the engle of the arm to the pullrod shouldn't exceed 100 degrees. If it does, check the lining for wear. Also ensure that the top of the rear brake pedal is approximatly 1/16th of and inch below the bottom of the right foot peg. Brake pedal travel should be 3/4" to 1-1/4" when pushed on lightly.

The front brake master cylinder can be difficult to take apart, as the snap ring that holds the guts in is pretty deep inside the cylinder. I found it much easier to remove by holding the master cylinder with a vise, (soft faces to avoid damaging, warping, or scratching the master cylinder) having a friend push the plunger in with a long thin screwdriver, and reaching in with the snap ring pliers around the screw driver and extracting the snap ring. you need some long nose snap ring pliers to do this. Replacing the parts is pretty easy. It might take a bit of lube to get one of the seal to slide onto the plunger shaft. Be careful not to bend or damage any of the leafs on the check valve/plunger. Slip it all back together and bleed the system. I tried gravity bleeding, pump bleeding, and every other method. No such luck, spongy, spongy, and spongy, I couldn't get that last bit of air out of the system. Then I tried a vacuum bleeder and had firm brakes in about 3 minutes. These things are GREAT!