I have a 1991 FJ80 (3FE) that has started blowing cool as opposed to cold air, as well as blowing the high high air relay. I checked the sight glass and with the air on the second highest setting I am seeing alot of air bubbles so I know I am low on freon and that I must have a leak somewhere. No mechanics near me are willing to even look at it, is there a way to find the leak myself? I really don’t want to go through the expensive process of converting to 134.