Check the main "kitchen roll" filter isn't clogged which is on the left hand side of the bag when the bin door is opened. There could be a clog, either behind the pick out metal grid below the filter roll, or the roll filter requires to be replaced. Can you add more info about the squeaking though? Is it a high pitched squeal all of the time or just intermittent and where it seems to be coming from - it could be excess air escaping from a pierced hose or a drive belt issue.