MaCa said:
its onli when i slightly pull the trigger!
Yeah... It's more a vibration right?
Vibration at the first point of pad contact is both very annoying and hard to get rid of. It's usually due to something being out of alignment or a bolt being loose. The brake mount on the frame may need to be faced with a proper tool.
Check all rotor and caliper mount bolts for proper torque. You could even go a step further and remove the rotor and caliper, clean all surfaces and then reinstall and tighten to the correct torque.
Then try aligning the caliper...
1. Make sure the wheel is properly seated in the dropouts
2. Check the pads to be sure the pistons are pumped out of the piston bore by an even amount.
3. Loosen the caliper alignment bolts just enough to allow horizontal movement with force. This will minimise/prevent the caliper moving when the alignments bolts are tightened. If you do what's in the manual, you'll tear your hair out...
4. Align the caliper centrally over the disc.
5. Tighten the caliper alignment bolts.
I hope this is helpful.