Finding leaks in engines, hydraulic systems, transmissions, and refrigeration equipment is easy with Tracerline fluorescent dye.

You just add a bit of the dye to the existing fluid, run the machine for a bit, and then use an ultra-violet light to spot any leaks. There's no need to clean off the equipment first.

In addition to diagnosing leaks, the company says you can also use it as preventative maintenance by adding it whenever you change fluids.

Tracerline leak detection can be used on virtually any fluid, including water and other clear liquids. One exception is brake lines, where it can't be used.

Different products are used on different systems. The process was invented back in 1955 but is not widely known among "shade tree" mechanics, according to the company.

Tracerline products are available at most automotive supply stores.