I have a 1993 C1500 Chevy Suburban. I have noticed that the coolant in the reservoir has been disappearing slowly over the last couple of days. I looked around for leaks and it doesn't drip a drop. Mileage is 170000+. Overall she runs like a dream except for the occasional "chugging" when I am on the freeway. It almost feels as though the engine is hesitating a bit. It only seems to happen at 60-65 MPH however. I am thinking it is related to the coolant disappearing. I am not the most mechanically inclined individual, however I can usually figure stuff out pretty quickly. If someone could possibly offer some suggestions so as to point me in the right direction I would really appreciate it. Thanks Maddog UPDATE: I found a leak coming from the front of the engine. There is a large hose going from the lower left-hand side of the radiator to the engine block. I looks as though the hose may have begun to work itself loose. If this is the case, could that also be the cause of the hesitation I noticed. It started hesitating a whole bunch, but only after it had warmed up a bit. Thanks!