first, look at the gaskets. are they "smushed" looking or dry rotted? and also the smallest particle of paint, and i mean small can casue issues. in most cases so small u cant really see it. take a pipe cleaner with " fine" bristles, soak it w/ cleaner then run it through the barrell of ur brush severla times. then inspect it for any discoloration. if u see some spots still use a dental pick or a sewing needle and VERY gently scrape it away. do this w/ all parts metal " needle, barrell, tips, needle guide tip etc" does ur needle feel " hard" to push through the brush?? if so t hat can tell u that u still have a clog or possibly even a bent needle tip, so inspect ur needle as well.... and if u have a local hobby shop that sells pacche they should stock ur replacement parts. if not u can go to there website and get some things there....let me no if u need more assitance. ill be glad to help :cheers