Electric hood problem

My electric hood has slowed almost to a halt. It's ok going back but virtually stops going forward. Could it be a matter of lubrication or if not can the mechanism be repaired?

I'd unscrew the T shaped valve on the pump and see how freely the hood moves and lubricate to get it moving better. If its free moving anyway then look at the pump and hydraylics. If there enough fluid in the resevoir? There are some pics of the pump on the site somewhere, do a search to find them. I would but work have just installed a web wilter that blocks photobucket pics from showing, even the emotions/animated gifs on this site are blocked for some reason!