AC worked fine for years, now low on refrigerant every few months
I have a 3 ton split system that's about 8 years old. Never had a problem until this summer. Tech came out and said it was low on refrigerant, added 2 pounds and it cooled great for a couple months. Now it's struggling again and I'm pretty sure it's low once more. They didn't mention finding a leak last time. Is it normal for a system to just start leaking after years of no issues? Should I pay for a leak search or just keep adding refrigerant every few months until I save up for a new system? I don't want to waste money if the whole thing is dying anyway.