Adding R134a?

[gnonne]

We hit some all-time high temps the past few days and our 2012 Sonic's AC systems worked OK, but not great. The cars are 6 years old.

I got a can of the R134a with the oil and followed the directions. Finding the low side port was easy, but its at an odd angle in the engine compartment.

On the first car (the one I drive) I got it up to pressure pretty quickly and it blows ice-cold. The gauge would go to the top of the dial when I pressed the trigger and then I had to press on the connector a bit to get it to release the refrigerant from the hose into the system (gloves = yes.) By the end I got coordinated better...

Second car, it seemed to not connect well, worse than the first, and I could not get very good readings from the gauge. I blows pretty cold and I have about half the can left after working on both cars, so I don't think anything is overfilled.

Any one else have any issues getting the supplied hose to connect to the port properly? Seems like this is the issue.

Thanks

 

[Italianjoe1]

Probably a bad connector on the hose you had. What types of pressure were you seeing?

In general, A/C systems don't lose refrigerant unless there's a leak on modern cars. Just adding more refrigerant won't make it colder unless it's very low usually, it's all about pressure differential and temperature drop. I would normally advise against just adding to the system using those parts store cans, without knowing where your pressures are, having too much refrigerant is just as bad for cooling efficiency as having too little.

 

[gnonne]

Got the connector to work better on the second car today - bright daylight helps quite a bit...

1st car, with AC running on high recirc, I was at about 25-30 psi on the low pressure port. Chart relating ambient temp and recommended pressure showed 45 psi, which I did get into the system. Nice and cold now.

2nd car was at 30-35 psi, could not get a lot more pressure into the system as the can was low, but got it to about 40 psi.

Cars are 6+ years old, so I think they did lose some pressure over time, especially in all the hard freeze/thaw cycles we get in winter. Most years we get at least 100 degrees difference between summer highs and winter lows. You probably don't see that in FL.