If your engine, radiator, or pressure cap may be losing coolant, or you suspect some overheating problem, then the cooling system pressure tester will come in handy. Attach this to the filler neck on your cooling system, pump up a little pressure, and see if the system will retain the pressure. Otherwise look for the fluid leak point. The same tool will also test the pressure cap.

This tool may be in the $60-$90 range. If you don't want to buy the tool, any radiator service shop can do the pressure test in a few minutes, maybe even as a free service.

For more information on cooling system pressure testing see article CO-106