PC overheating; using liquid coolant

[Ganondorf]

I'll preface this by saying that my computer hardware knowledge is about 20% of what it should be.

I've had my pc for approx 2 years with no trouble. Tonight, it's been shutting down after about 15 minutes of activity (shuts down, but remains powered). I popped off the side panel and noticed the Liquid coolant pump (Asetek) and tubes are really hot. I've never had a problem before, and never bothered to check, so I can't offer a comparison, but they feel like hot pavement to the touch. The motherboard fan is not running, though I'm not sure if it ever did work in conjunction with the coolant, or if it's just there as a backup.

Does anyone have experience with these? Can the pumps go bad or do I need to worry about coolant levels? Is there a generally reliable place I can take it for repairs, and is it even worth sticking with liquid coolant? Any help is greatly appreciated.

[Criosist]

some pumps become weak and cannot begin flow, try if you can lifting the pump above the area the outlet of the pump is connected to so that the start of the out is going down rather than up and if this worked you should hear water suddenly flowing