Is it normal for my AC to take 10 minutes to finally cool off the inside of the truck?

For one, I live in the south where it gets very humid, which seems to compound how hot it feels. I know the truck is 20 years old so I don’t expect it to be perfect, but even when I’m at operating temp it still feels as if the AC is lacking. I have already cleaned the coils out underneath the glovebox and it helped slightly, though it was very hard to even get all the gunk/trash out through the little hole and there’s probably still gunk in there.

I thought maybe my system was low on refrigerant so I purchased two different brands of refrigerant. (* reason being for buying two- I wanted to see how the pressure gauges compared to each other, and wouldn’t you believe it, they both read the exact opposite of each other)*

I don’t know what to make of these 2 readings. One says it’s past full, the other says it’s so low it won’t register. I took the readings with the car on and AC at full blast

Im a little scared to fill it with refrigerant at this point. I had the system recharged 5 years ago in a friends garage (done with “professional equipment “)

 

Unless you have proper training and equipment, I would advise you to take it to a specialist AC repair shop.

 

The second pic, you're taking that reading with the AC running, right? Honestly, it's much easier to do more harm than good unless you know what you are doing with these. Those LAPS AC refill cans often contain a lot of crap that do not help your AC at all. Do some research on local AC places and have them at least diagnose it.

 

Both pictures are with the car running and ac on full blast. The reason I bought 2 different gauges is because in my mind I thought “ I bet if I buy 2 different brands of gauges I’ll get 2 different readings, so I’ll just take the average from the 2 to get a more accurate reading “

Well I never excepted one to say it was empty, and the other to say it’s past full….

 

Never use the cheap gauges supplied with the refrigerant in a can, they never read correctly. Always uses quality gauge.

Definitely take it to a reputable shop if you feel it’s not blowing cold enough. They can discharge the system and refill it with refrigerant with added UV marker dye. You then come back in a week or two and they’ll point out the leaks in a system.

You can then go from there how you want to proceed. Live with it, pay to get O-rings and and schrader valves replaced as an example or figure out how to do it yourself although you’ll need a garage to discharge it so you can work on it then refill it.

 

Given the cooling area of your Sequoia is close to almost double the area of even a 1st Gen Tundra DC, in these 100 deg high humid days, I'd say 10 min's is not too bad. Since this is a Sequoia, are you depending on front AC only or is your rear AC helping out. If your parked outside in this scorching heat, factor that in also. Knowing what degree is actually coming out the center vents would help knowing also.

I'll also agree with others that AC for some folks is best left to a professional in that business.

 

You can get a thermometer and put it in your vent to find out how cold your AC blows. Something similar to this

$8 Interdynamics Certified A/C Pro Car Air Conditioner Test Thermometer, Helps Diagnose AC Performace and Checks Outlet Duct Temperature and Ambient Temperature, Includes Holder and Clip

Air Conditioner Test Thermometer. The amount of space and different cooling vent zones will play a factor. If you're sitting in the driver's seat, does it still take 10 minutes or more to feel a significant temperature drop?

 

An example of my leaks (green) when using a UV flashlight (purple).

 

Too much or too little freon and it wont get cold.

 

I second the opinion to put a temp gauge in the duct, that's the only way to tell the temp of the air coming out. I have a nice analog style in my vent and it's always around 40 F. I'm in SoCal where it's hot, but not too humid most days. I would take it to a specialty air con shop if in doubt of the system. FWIW, my 24 Y/O air con system has never been serviced, still on the factory charge.

 

Third...get a temp probe and measure the temperature from the vent. Should be ~ 45 - 50 degrees.

Also, turn on air re-circulation so you're not trying to cool ~ 100 degree air from outside the cab.

Also, check your fan clutch.

 

same