I have changed the clutch Master and slave.

The question is n't very detailed, but it sounds like you need to rebleed the system on the clutch. Best way is to power bleed available at alot of auto parts stores, but you can also take the bleeder out of the slave and let it gravity bleed, then reinstall it then pump the master and bleed it normally. If that doesn't cure it then it may be a bad clutch or worno out release arm.