Screwdrivers are one of the first basic tools you will use when working on a refrigerator project. With a screwdriver you can open most of the refrigerator panels and undo a number of different screws and bolts that may be holding pipe assemblies together. Depending on your refrigerator, you may need to use either a Phillips or flathead.
Having a few wrenches to use along with your screwdrivers is not a bad idea -- some bolts may be designed to be removed with a ratchet wrench, for example. But if you are fixing a piping problem you may need an entirely different set of wrenches, known as valve wrenches. These tools will help you detach and replace any valves that your refrigerator uses, an important step for making many repairs.
If you are lucky, you will be able to buy replacement pipes that fit perfectly into your refrigerator and solve your problem. But if the pipes are more generic and the fit needs to be customized, you might need a welding kit in order to attach the pipes to your refrigerator system with an air-tight and water-tight seal. This includes not only a welding gun, but electrodes, solder wire and any other necessary accessories.
It is often useful to find out where a problem is located before you start replacing sections of pipe. You can use gauges to measure water pressure and, even more importantly, refrigerant pressure in your refrigerator. This can help you diagnose potential leaks and ascertain when leaking problems have been fixed.