That's the advantage of the dye. It shows up where the coolant doesn't, typically because the leak is so slow that the coolant evaporates before it can form a puddle. You can buy the dye at auto parts stores. There is one for petroleum-based oils like engine oil, transmission fluid, and power steering fluid. Another one for glycol-based products like brake fluid, and one for engine coolant. Many auto parts stores borrow or rent tools and they will likely have the black light.
A lot of engines have water pumps that are driven by the back of the timing belt so they are hidden by a plastic cover. There is also a tube plugged into the backside of the pump with an o-ring that can leak. The clue there is the lower radiator hose will attach to that metal tube on the driver's side of the engine above the transmission.
Wednesday, May 1st, 2013 AT 1:46 PM