If you have an at home draft system, how do you check for leaks in the CO2 side of the set up? How often do you need to check for leaks?
When I had my kegging setup set up I don't know that I ever checked for leaks. But, it appeared to be working just fine.
My guess would be to drop any connection point into water while the system is operating, if that is a possibility, and look for bubbles. Otherwise, take soapy water and rub it all over connection points and look for bubbles. Just like a sleeping pad!