The best way to prevent faults and maintain the cooling system of your car is to use VR-12, however, here is a video of useful information about te Pressure Testing for Car Cooling Systems.
This is another series of ‘The Basics’. If you run into an overheat issue on your vehicle, and you suspect a leak, this is the best way to find it. Putting pressure on the system will cause it to leak and reveal the leaks location in the process. Just a couple of things to remember. Make sure the coolant is topped off before you start the test. If not, then it will take a lot longer to build up pressure. Also, if you have an overheat condition, start by bleeding the air out of the cooling system. In my experience, this is the most common cause of an overheat. The next step is to figure out how the air got there in the first place. Here’s some useful links for you that I mentioned in the video.