Filling an AC system for the first time

[Waverous]

Who has done this before?

I purchased a complete system for AC fill from Harbor Freight (Gauges and pump), and now I would like to fill my system. Are there any tips, advice, web sites anyone can recommend?

 

[Broncobowsher]

Don't let air in after vacuuming.
Don't overfill. More is not better. If you get too much in, there will be liquid refrigerant coming out of the evaporator and if that makes it into the compressor. Well compressors don't like to compress liquids and they blow up. Ideally you want the suction like to be ~5° warmer in actual temperature the temps scale on the suction scale of the gauges. At this point there is cold gasses going into the compressor, but warm enough that it isn't liquid.
Don't liquid charge (inverted can). It's faster, but blows up compressors. Bucket of hot water to heat the freon in the can and send in as a gas is best.

 

[Timmy390]

100% amateur here........

Chart for R134a pressures
https://rechargeac.com/how-to/ac-system-pressure-chart/

I've rebuild one once. Assuming R134a, get the right oil for the system ( Polyolester oil (POE oil) as I recall). I used A/C PRO PY-7 R-134a ESTER 100 Refrigerant Oil with ICE. How much, 15% of the compressor's original oil capacity.

I sucked the system down for a long time to get the moisture out. Closed everything off to verify no leaks. Then gassed her up. Had the car for another 5 or more years and no issues. A/C was super cold. I used the HF tools to do this.

Good luck

Tim

 

[4xfun]

Youtube is your friend. Try this one

and

.

You may have to use a jumper wire to trick your compressor into turning on.

 

[Broncobowsher]

Pulling a vacuum does not get rid of all the oil in the system. It pulls only a little bit. It is incidental as the freon is vacuumed out it foams a little bit of oil and that is all that is pulled out. Every new compressor I have installed in 20+ years came pre-filled with oil. Generally a little oil is needed to wet the lines. But screw up is over oiling, full load of oil on top of existing oil. If you roll the compressor around with the plugs removed and oil runs out, it is pre-filled.

Aftermarket systems probably don't have a sticker with a charge amount. That is where things can get tricky.

 

[Waverous]

Man! Thanks, everyone! Great advice and tips!