Just fitted new front and rear brake pads and also done a full brake fluid flush . All fine with rear but something strange with front . As per the BMW manual I set the pistons back in the caliper then bled the master cylinder , RH caliper then LH caliper . I then using the GS-911 did the brake bleed function to cycle the ABS valves . I then re-bled the whole system again . Brake lever is firm , with pads back in braking is good , however on applying the brake lever as if you were doing an emergency stop .i.e very hard I am getting a noise out of the feed and return brake lines to the ABS unit . Only makes the noise when pulling lever very hard . I ended up doing the whole bleed cycle over again another twice , no air bubbles coming out of calipers or master cylinder bleed nipples , but after pulling brake lever hard and getting the noise I do get a very tiny amount of bubbles and i mean the very tiniest amount coming out in the master cylinder reservoir . I have left the bike with the brake lever tie wrapped to the handlebar overnight to see if it is some trapped air but was wondering could the noise just be the abs valves as it only happens when i pull lever very hard ? Any thoughts welcomed . I have not noticed the noise previously but i do have the bike fully stripped at the moment - no tank , no fairing panels , no headlight or clocks so noise would be more easily heard at the moment
