Are you sure you have air in the system? What if your hoses are old and weak and expanding when you pull the lever? Or what if your master cylinder is worn and passing fluid past the piston? Just some possibilities. What I usually do after bleeding is to pull the lever back as much as I can and tie it to the handlebar and leave it over night. This opens the port in the master cylinder and any air bublbles left in the system rise to the reservoir.