Fluval Q2 air pump problem

[kusumuck]

Hi. First time poster, long time lurker. I've had a Fluval Q2 for about a year and a half working great. Lately though it seems to have lost most of its power. By most I mean it won't pump the 18" down into my 75 gallon tank into an airstone UNTIL I squeeze in just the right place on the bottom. Looking at the bottom of the unit is a rectangular inlay of plastic that looks like it might be a separate piece of plastic from the housing. Pushing on the edge of that rectangular inlay makes the pump work as it should. I tried taking it apart and tightening the screws inside and then the screws on the outside but with no change. I still have to push on it to work. Right now I have a 8" C-clamp holding it with a little pressure and its working fine but that isn't a permanent solution. Anyone have any experience with this particular pump or anything similar? My fishies and I thank you.

[kusumuck]

Anyone have any ideas what causes this and/or a fix for it?

[woo2]

I have exactly the same problem. I have stripped the pump out but can not see anything loose or not sealing properly. Any solutions would be much appreciated....