you need to bleed the air out of the brake lines and caliper,fill up the master cylinder and pump it several times and get someone at the back of the bike to undo the bleed nipple on top of the brake caliper then do it back up keep doing this procedure until the brake is firm to pull ,tips
dont get it on paintwork it takes off the paint or dulls it and make sure the fluid doenst run out in the master cylinder or you will be back at the beginning again.dont expect it to be a quick fix it can take up to half hour to bleed as the brake pipes are micro bore types.
adam bike doctor, May 2009