Caliper Knocking

[ConTRo13R]

Whats going on here

Its not the wheel bearing as iv had both calipers off and the wheel spins freely, no notches, right hand side caliper attached, spin wheel, its fine, add left hand caliper into the mix and this happens. Most annoying whilst riding around town.

I have replaced all seals and bleed the lines though i think one of the pistons is still sticking.. when i apply the brakes i have full braking power and no noises of judder. just when i release the brakes then this constant knocking noise seemingly every wheel rotation.

Video link:
http://youtu.be/pnQ6d6ru090

 

[ConTRo13R]

Yeah warped disk or something? turn the wheel really slowly, do you get more resistance trying to turn the wheel when it reaches the knocking bit?

A lot of resistance just before and slightly during the knock, If i bought a new disc would i need to replace the other side too? or just the pads.. this is depressing as i need a new rear tyre and chain, and have my MOT next month

 

[ConTRo13R]

warped disc or loose disc buttons

By loose disc buttom do you mean the blots holding the disc to the wheel/carrier

do you have any little spring plates/shims etc in them?
any missing
had something similar and it was one missing spring plate, letting the pads rattle around when the brakes weren't being used

both my plates that hold the pads are in place, the calipers don't have any shims on them and never did.

 

[ConTRo13R]

I would say that the noise is coming from the caliper moving on the pins once a certain point of the disk runs through the pads. Iv found one point on the disc that once having passed through the pads the caliper pushes out and then knocks back in. Is this definitely a symptom of a warped disc?

Iv already replaced the seals and cleaned the pistons in the caliper, although one piston is definitely more reluctant to move than the other so may need to do a better cleaning job when i next get a day off

New OEM discs are 125 form David Silvers, bike is a CBR 600 F3 from 1997, i use it everyday as its my only mode of transport.

 

[ConTRo13R]

replaced all seals on all pistons on all calipers. I had this problem about 3-4 weeks ago which is why i replaced and rebuilt the calipers, the knocking went away and is now back with a vengeance! So looks like a new piston and a new disc for xmas