It's gonna be the accumulator I bet. They tend to rust out. It's not really expensive IIRC, somewhere b/ $65 & $75 bucks for the part.
EDIT>Jsut noticed you're in Canada... Not sure what it'll cost you in CAD, but still not going to be expensive. However, with most of the hot days of summer gone I would wait until the spring to replace it. It's the friggin' salt that really accelerates the rust on the thing. It will rust out down south too, but I'd let the new one you'll need to install skip this winter just because...
Last edited by Tisby; 08/29/06 06:30 AM.