Reef Octopus Skimmer not producing bubbles

Hi,



I have a reef Octopus RS-PS2000INT Skimmer. It was working just fine all these days and suddenly its not producing any micro bubbles. The pump is working, but no bubbles. I tried cleaning up the air passages and removing the impeller and cleaning it thoroughly. But still no micro bubbles.



I hear a squeaking sound in the pump. Any suggestions? Please Help!!!



Thanks,

Harish