Rebleed your system starting with the rider's left brake cal, right cal and then master. Youve probably got air in the system somewhere. If not, you're gonna have to take a look at the master cyl and cal pistons. Seals may be deteriorating. If youre rotors happen to be warped or you need new calipers, I've got a set off my 05 I'll sell you. FYI, the stock tokicos are pieces of shit. Replace them with some monoblocs if you get the chance.