Ahh yeah mine is a creaky bastard haha. Well, something is inside the bell housing/ slave cylinder. And yeah I feel it in the pedal big time.I think they mean Slave Cylinder. The MC feeds the slave cylinder through the sleeve in question. I had the sleeve changed and had that protective cover put on it but the actual slave cylinder is still all jacked up. once it gets up to operating temp or anytime during the warmer months and summer it is spongy, sticky and creaky. Its almost like the seals inside swell and cause issues.
But, i am no engineer and the dealers cant find any problems with it so...
Dealer actually replaced my master cylinder in an attempt to fix it but didn’t work.