Adding R134A to A/C
My 1999 Mazda Protege A/C works, but being almost 10 years old and by the "hand test" I think it may not be up to specs on cooling temperature, so
From Walmart I purchasedd on 10.4 oz can of Interdynamics 134a with Leak Sealer refrigerant with a simple trigger cap and Low side connection hose. I started the car and measured the A/C temperature at the dash, it read about 50 degrees with the outside temperature in the low 80s, plus the sun heating the car. The windows and one side door was left open, so the A/C was working against a solid 80s temperature, i.e., cooling was a bit over 30 degrees.
I connected the refrigerant can to the low side of the car's system via the supplied hose, after removing the dust cap on the car low side. The supplied hose/connector "snapped" on. I then shook the can and pulled the trigger: I could hear a slight hiss, then nothing as the engine was making enough noise to cover any flowing sounds, but I did sense a slight vibration to the can and a cooling. After about a minute I released the trigger and heard a brief hiss, I shook the can some more and pulled the trigger again. I did this repeatedly until the can felt light, it would still cool down and hiss when I released the trigger, but I figured most of the refrigerant was dispensed.
The air temp out of the dash dropped perhaps 2 or 3 degrees, not sure that was due to the additional refrigerant, or due to just the run time, now about 10 minutes. I suppose the A/C output temperature would go down more at driving RPM.
Questions: should it take several minutes, perhaps 10, to dispense 10.4 oz from a can of refrig? Do I really need to get a pressure gauge, even Walmart sells Refrigerant in larger bottles with a reusable hose/guage.
I'm thinking drive the car some and see if the A/C is working "well enough". At this point besides the gas and $10 for the refrigerant/dispenser all I have invested is about 30 minutes of my time, maybe 40 minutes counting this posting.
I didn't see any leakage, but the can I purchased said sealer, it said nothing about a "red detector" color..must not have provided that. I don't think there is any leakage as the A/C works, not dead.