alright im new to Volvo's, whats happening: my 93 850 is leaking coolant but not overheating, it seems to only leak it when I really hammer on it hard and the coolant light comes on and the level is low. there is a crack in a piece of plastic that has small ridges next to flat spots kind of like this shape ____||____||____ about 5 inches below the cabin filter i mistook it for my ratiator last night. when you squeeze the hose that runs along the cabin filter hose it comes out of the crack. what is it. its right down there next to that big cilinderlike thing that i forgot what was. hope someone knows what I mean.