[Rich in Vancouver]

My wife had a PT Cruiser. When you wiggled one of the AC pipes gently you could hear gas escape. The connector was in a spot that was very hard to get a wrench into so I never tightened it up but it must not have been affected by vibration as the system never needed recharging.
On re-reading this thread I think Stocktake nailed it with the garage using the term "up to". That's a B S marketing term meant to scare people into doing jobs that probably don't need doing.