AC fully charged blowing 80% cool. No more, no less.

[runnyrunnerton]

Please use search function comments sparingly. I searched and the valve name I'm looking for and how to check it has remained a mystery.

My 97 runner AC has been ice cold since day one. I recharged it regularly in May every year and didn't need to mess with it until the next year. Last year I used R134a with stop leak against my better judgement. The ac worked great all year no drop off, This year it was working great until about a month ago.

One month ago I took my trusty 134a auto zone filler special on a hot day and noticed something odd. System fully charged according to the cheapy pressure gauge? I fooled with the fill valve, some refrigerant escaped (whoops) and i filled it back up (only lost about 5psi). AC got cold for a few mins and warmed back up. It stays pretty consistent at about 75%-80% cool. Pressure checked at all times of day. Fully charged.

What am I missing? I can hear the mix gate working, but I have no idea what could be going on. My searches lead me to believe there is a stuck valve, but no one names it, the remainder of advice consists of filling the ac system and checking for leaks. Mine doesn't leak, the pressure is good. Any help would be appreciated.

 

[BlackCat914]

Bubbles in the sight glass? Are the condenser fins clean? Fan clutch functioning properly?

BTW, if your system doesn't leak, there should be no reason you have to fill it yearly.

 

[chadsy]

I've been doing a lot of research for my upcoming AC project. If you HAVE to recharge your system each year there's deff. a leak somewhere in your system and that could be straining your compressor. If you are adding it in just for the hell of it, from what I've heard, this could be just as bad as not putting enough refrigerant in it.

I think you may be talking about the expansion valve? Sounds like your compressor may be in the early stages of crapping out.

Is your compressor engaging at all?

 

[Skidmarcx]

You need to get us true pressure readings from AC gauges in order to help diagnose... Using that quick fill can will just get you into trouble in most cases

 

[Singtoe]

Disconnect your heater valve cable and turn the valve to complete to the passenger side.

You might have a broken valve.

If you can't disconnect, use some locking pliers and pinch the heater hose shut.

Test the AC.

 

[Singtoe]

So what happened?