[snowwy66]

It's recommended to change the receiver dryer anytime a part is changed. More with the compressor though. It's a filtration sort of like thing in the system. For contaminants and moisture.

If you know your ac is spinning and you're not getting cold air. It's either low on freon or something is wrong. It only takes 50 pounds of pressure to kick the compressor on. A fully charged system with compressor off will sit at around 110 pounds. Give or take a few pounds.

So, just because you see the compressor spinning. Doesn't mean it has enough freon to blow cold.

My 17 cruze bought new 9 months ago only came with 60% charge. It wasn't anywhere near cold that it is now. With a full charge.

 

[snowwy66]

@Taxman

I suggest you read the book and stay away from google and youtube.

Subcooling

That word isn't even used in the book. Nor was it on the test I took to buy freon. And nobody recalls it being mentioned in the first book we had to read to buy freon 26 years ago either.

FYI

 

[snowwy66]

I suggest you pull your head out of the 20th century and quit claiming your ignorance of modern industry standard service methods is wisdom.

EDIT: On second though, that sounds too harsh. You called me out by name so I threw it back at you, but it doesn't help anybody who's wasting their time reading it.

In automotive systems (and ductless mini splits), all the parts are known to the designing engineers, so they specify a charge weight. The technician evacuates the system and puts the prescribed number of ounces back in. Quick, easy and accurate.

In building HVAC, parts are more mix and match, so if they want to get it right, they set the metering device by superheat, and they set the charge weight by subcool. If you want to substitute your judgment for that of the engineers who designed it, take this route, if you're just following a number on the red pressure gauge you're flying mostly blind.

Overcharging just adds head pressure and power consumption without doing much for performance.

I suggest you get some experience.

Going blind. THAT'S FUNNY.

Those recharge kits on the shelves are going blind.

But I'll let you in on a little secret.

The new 21st century way puts a car at 250 - 275.

The sweet spot always comes in at 225. ALWAYS.

Last i checked. 225 was lower then 250 - 275.

Since you can't do the math. 300 would be overcharged. 225 is undercharged.

Get yourself some gauges and a meat thermometer. You'll quickly learn.

The coldest point. Would be undercharged.

The gen2's call for 18.145 oz. That's 255. The sweet spot is 17 oz. That's 225. And THAT my friend. Was done the 21st century way.

You see. I can do that. Cuz i have ALL the equipment.
Full analog and digital gauges with a databank that contains capacities for 55 makes and models. Should the car NOT have the decal it was shipped with. 30 lb cylinders of freon. A freon weight scale. Vacuum pump. Thermometer. And access to a recovery machine anytime i want.

Overcharge has never happened. And it's unlikely to happen in the future.