Gotta diagnose exactly what is leaking to determine the cause. The typical things would be a gasket started to leak and the slippery coolant allowed the belt to slide off a pulley, the belt came off due to a misaligned pulley and the water pump is driven by the belt so after a couple of minutes the engine overheated and pushed expanding coolant into the reservoir where it overflowed, and the belt came off and slapped across a rubber radiator or heater hose repeatedly until it wore a hole in it.
It is also common for the water pump to develop play in the bearings. That lets the pulley wobble so the belt slips off, and the shaft wobbles away from the seal so it leaks coolant. That coolant leak would start out rather slow but the belt will suddenly pop off without warning when the wobble gets bad enough.
If the leak is rather significant, a pressure test will show where the coolant is sneaking out. If it's a real slow leak and the source isn't obvious, you can add a small bottle of dark purple dye to the coolant. After driving long enough for some coolant to leak out, you search with a black light. The dye will show up as a bright yellow stain. All auto parts stores will have the dye, and many borrow or rent tools. Those will have the black light.
Monday, November 4th, 2013 AT 12:38 AM