We're a two-RDX household, my girl's '15 and my '11. Recently I moved hers from the drive to the street and I was astounded at the immediacy of her AC; cool air RTFN! Mine on the other hand takes a bit to get the air temp down and seems to struggle on a hot day. Since my kid and I are about to make a 5-6k road trip (Montana here we come) I decided to see if I could improve the performance.

Using the FSM as a guide I determined that both the high and low pressures were low and that the delivered air temp was higher than specified- clear signs of low refrigerant.

After adding ~85% of a small can of R134 I'm pleased to say that my pressures are now in line and I lowered the temperature of the delivered air by 7*F; probably the best $6 I've spent all summer!

 

Out of curiosity what does the service manual say the pressures should be? Mine is older and seems to have a very slow leak at the low side port.

I think it has an expansion valve because the pressure comes up to around 25 pretty easy but doesn't increase quickly beyond that. I have just charged it very slowly and went by the vent temperature, being careful not to overcharge.

Last time I discovered the AC Avalanche brand made mention of expansion valves and had the Smart Clip color changing vent clips. I used that and the charge level and feel at the vents seems pretty much the same as getting up around 25 and then feeling the vent temp with my hand. But this is easier and I don't have to second guess feeling, or try to read pressures or temperatures not knowing what they should be. The clips are also reusable so I don't have to guess rather or not my wife has menopause or the ac needs a shot of refrigerant next time.

Anyways, I was wondering what the service manual says for pressures. I don't know if Acura actually uses expansion valves or not. That was just the thought I arrived at by adding slowly. If they do, we should post something of a warning to make a sticky so people don't go accidentally overcharging and killing their system trying to get the pressures up. Most brands make no mention of this.

P.S. It is also a good idea to have something to pull a hot relay and some spares for the AC and fans, etc... or change them preemptively. I had my A/C go out on the return part of a trip. Ended up figuring out it was the relay after I got home. I could have been a lot more comfortable if I had known to have something to pull with and some spares, or changed them out early.