I had that problem a few weeks ago. One of the hoses disconnected, so there was no pressure. The fluid was just leaking out into the engine bay. Got the hose reconnected and all is well.
I had it checked out at Jiffy Lube. He said the connections were all tight and there were no leaks. Got an estimate of $200 to have the pump replaced, but I think I'll check around and see if I can get it done for cheaper.