Bleeding front brake...spongy no matter what!

[Luddite]

Originally Posted by Bitza

.I also tried to suck the fluid down through the system via the bleed screw, but I found that I was sucking air in via the thread of the bleed screw.

Apply PTFE tape to the thread and try vacuum bleeding them again.

http://www.ukmonster.co.uk/monster/s...d.php?p=577122

[Darkness]

Originally Posted by Luddite

Apply PTFE tape to the thread and try vacuum bleeding them again.

http://www.ukmonster.co.uk/monster/s...d.php?p=577122

Pedro has been having trouble with a soggy back brake on his M1200R.

He has solved it now though:

‘ stumped up for a new master cylinder and swapped it over and also fitted the Stalhbus nipple, low and behold I have a decent rear brake again, not ridden it yet (prob tomorrow) but the pedal has remained firm for a few days (normally goes a little mushy in a week).

but... omg, how flipping good was the new bleed nipple! System was bone dry, undo bleed nipple 1.5 turns to fully open the ball valve and use a vacuum pump to fill the system, took about two mins, close the nipple fully, pedal felt quite good. Onto “bleeding” it, open it half a turn so the ball valve is in play, pumped through a couple of reservoirs of fluid, close valve, pedal good and firm. Chuffing marvellous!!

I pulled the old cylinder apart to see if there was anything obvious wrong with it but nothing other than some uneven wear in the bore from the naked eye. I still think it was letting air in, perhaps via the reservoir connection but not sure.’