My car started overheating yesterday and then today the coolant light came on. When I checked the coolant today, it was below the minimum. I tried putting water in there but the car started overheating soon after (within 5 minutes). I checked the coolant and now the coolant is WAY less than what it was before. There's barely any and there seems to be a leak coming from directly under the reservoir.
Then I discovered this:
http://i.imgur.com/AbOpA.jpg
I'm 99% sure the leak is coming from this hose. Is this supposed to be connected to anything? Or is it supposed to prevent the reservoir from exploding due to pressure if the coolant gets too hot? If so, why is my coolant getting too hot and expelling liquid from this hose?
Then I discovered this:

http://i.imgur.com/AbOpA.jpg
I'm 99% sure the leak is coming from this hose. Is this supposed to be connected to anything? Or is it supposed to prevent the reservoir from exploding due to pressure if the coolant gets too hot? If so, why is my coolant getting too hot and expelling liquid from this hose?