Yes auto air conditioning can be a do it yourself thing if you know what you are doing, wouldn’t say the same thing about house AC, must know how to braze copper pipe and have all the right equipment, just the recovery pump alone will set you back a bit.Some types of Freon are no longer available but they do have hybrids that don’t work as well. If the leak takes 3 years then I suspect it is on the low side which means the attic where the evaporator is.
