I've been reading online and I am very confused. Some say you should never recharge your A/C system if everything is operating properly. While others say adding pure 134a refrigerant/coolant will help with your cooling. My Mazda dealer says one shouldn't need to recharge the A/C either.
In particular, my 2005 Mazda3's A/C isn't quite as cool as it used to be. Additionally, in 2006 my A/C was checked at the dealer, discharged and new coolant with a dye was added under warranty for another issue. My understanding is that with the dye or lubricants, the A/C won't run as cool as one with pure coolant.
In Asia, where temperature extremes are normal, people get their A/C unit serviced and flushed too at the dealer.
Can someone shed some clarity whether or not recharging the A/C is necessary? And are specialty A/C shops are thing of the past now that can do the recharging without going to the dealer?