Just went through a search for leaks in my pitot static system. I started by reading the multiple post already written and learned some before and some after of what to do and what not to do. After I tried to check to see if I had leaks by blowing on tubes in the pitot system, I learned, never blow on the pitot system with an instrument attached as one may damage the instruments or the ahrs (airspeed, altimeter). Fortunately, I only blew with minimal pressure and I did not damage my system by trying to fix it. Also fortunately, we have a great number of really smart, knowledgeable aviation experts on this forum who have helped a not so smart aviation enthusiast.
I had available to me a simple manometer , made from a ½" vinyl tube (from lowes) with a yard stick mounted on the center of a vertical board. I did not know how to use a manometer but after a few tries and a little instruction, it worked like a charm, especially to see if your system would hold pressure.
My system is connected with 1/4" standard nylon tubing. I have a G3X, gap 26 heated pitot/AOA probe, GSU73 and GSU25 and a G5. I learned from our aviation experts to read the manual first, then disconnect the ahrs and G5 and check the legs to see if there were leaks. My connectors are push to connect (PTC) which I purchase at the same time as my instruments from Stein Air. I also purchsed som PTC from a local distributor that sell Parker PTC. All PTCs are quality and all PTC were solid and leak free. I learned the hard way that I thought one would need to disassemble parts of my RV7 (such as the wing root fairing and floor where some connectors joined) but if you will check from the ahrs, and G5 to the probe or the static ports (tape over the ports) first using the manometer and about 15" of water, if it holds steady, the no leaks. Also learned that one must cover the pitot tube (good seal) with both openings in front and tape over the bottom drain holes and AOA hole (my probe has 3).
The gap 26 (per manual) allows some leakage and again I learned the hard way ( I removed the probe and checked for leaks using a bucket of water but careful with the wiring) that my probe leaked what I thought was a lot. I really found my leak in the flare fitting at the end of the probe, that I allowed to loosen. When I reconnected everything (wing fairing, floor and probe) I found another leak at my GSU73 where I had a Tee with a physical fitting I had allowed to loosen. I added a little liquid teflon to the physical fitting and reconnected it. During my testing, I found it much easier to use a small amount of 1/4" vinyl tubing (lowes) when connecting to the PTC and the manometer. I used a large syringe to add water to the manometer to increase pressure (simply convenient and easy to increase the pressure in small amounts). When checking the PTC that were physically attached to the ahrs and G5, I would bring the airspeed up to 130-150 to make sure it did not leak (manual will allow some drops). Also learned that a golf tee works perfect to tap off a leg on tubing or a short vinyl tube with golf tee to check a PTC tee.
I do not think soap will work as easy or conclusive as the manometer and from my experience (soap before manometer) a lot messier and very hard to really see, especially a low pressure. If I had been smart enough to start from the ahrs/G5 and track backwards, I would have save a ton of time, effort and some blood as my RV has no sharp edges, screws and always plenty of room so that I never get scrapes and cuts.
Hope this will help some other not so smart aviation enthusiast.