I bought a pair of Clarks m2 Hydraulic disc brakes, pre-bled, and installed them on my bike. The rear brake worked great, good stopping power, but the front feels more like the mechanical disc brake that I replaced. Lever is hard and the stopping power is not nearly as good. I bought a bleed kit after being told the brake may not have been pre-bled properly. Went through the procedure (first time I have bled a brake) and now the brake works even worse than before. The lever is firm but the stopping power is lousy. I noticed when removing the bleed screw from the caliper that the screw was very tight and the o-ring fell off when pulling the screw out. Perhaps the seal is not good, allowing air to enter the system? Any help would be appreciated.
If the lever is hard but there is no stopping power, two things it could be (there may be more of course):
Brake fluid was spilled on the brake pads/rotor when bleeding. This is pretty easy to do if you dont take the pads out when bleeding. If you bled them again yourself for the first time you may have done this again (which could be why they are now worse). Check the brake pads and rotor to see if the have fluid on them. If so it is easiest to clean the rotor and get new brake pads. (This happened to me last week) some people clean the brake pads in an oven but that seems tedious.
Brake pads need to be broken in before they work very well. My guess is that your front brakes could have used thise before you bled them. Easiest way is to get up to high speed and lightly hold the brake for a while the press if hard until you stop. If you have a long hill nearby you could do this there. Or just on the street in front of your house.
And If the o ring near on you bleed screw is busted you should replace that