I replaced the front brake lever on my ‘05 CBR1000RR and bled the brake system several times. I even purchased and used a professional bleeder kit with a hand pump. The brakes continue to gradually build up pressure until the pistons on the calipers are fully expanded and won‘t retract. Even when I crack a bleeder valve to relieve pressure, they still build up pressure over time until I bleed some more fluid. What should I do?????
I would suspect the master cylinder is not releasing like it should. The master cylinder pumps the brake fluid into the calipers and when you let go of the lever fluid pressure should drop an allow the pistons in the caliper to retract There are rebuild kits for most bikes at a Honda Dealer
The prior post is most-likely correct, the bolt your using to hold on the new lever is too tight. What you don't want to do is loosen the bolt too much where the nut will fall off. You may want to find another bolt with a nylon nut so you can leave the bolt loose but the nut don't have the ability to fall off. If the lever isn't too tight then your master cylinder would be the problem. Usally there is a spring that will make the plunger return to its bottom location and releave the pressure in the lines making the fluid return to the reservior. so either your spring is weak or plunger oring is defective.
check rotor run out and verify that there is no junk inside the caliper piston bores
