digest
Short Summary
Main recommendation: If your car's air conditioning isn't blowing cold, check whether the compressor is running and whether the low side pressure is too low, then recharge the system with refrigerant, ideally after evacuating the old refrigerant and measuring the charge with a scale. The video presents a simpler gauge-only method as an approximate fix when the full equipment isn't available.
Key Points
- Start by running the AC on maximum with the blower on high and checking under the hood whether the compressor's front pulley is spinning; a non-spinning compressor means you must first find out why it isn't operating.
- Connect AC gauges to the low pressure fitting: a reading of about 5 pounds is well below the expected 30 to 40 pounds with the AC running, which the speaker says usually means low refrigerant.
- Compressors leak a small amount through their shaft seals, so occasional refrigerant top-ups are described as normal.
- The speaker says gauges can be bought for around $40 at places like Harbor Freight Tools.
- The preferred method is a full recharge with a vacuum pump and a scale, while the gauge-only approach is a fallback.
Details Worth Noting
- Concrete instructions:
- Set the AC to maximum and the blower to high, then look under the hood at the compressor's front to confirm it's spinning.
- Buy AC gauges (about $40 at Harbor Freight Tools, per the speaker).
- Remove the cap on the low pressure fitting on the engine, attach the gauge fitting, and read the pressure with the AC running. Target: 30 to 40 pounds.
- Preferred recharge: empty all old refrigerant with a vacuum pump, then add refrigerant from a can using a scale to measure the amount.
- Approximate fill without full equipment: connect a refrigerant can to the gauge, open it, and watch the gauge.
- Place a small thermometer in the vent closest to the middle of the dash.
- Stop adding refrigerant once the gauge reaches 30 to 40 pounds, close the can valve, and check the vent temperature. The speaker's result was about 38 degrees.
- The speaker says a compressor that isn't spinning needs diagnosis before any refrigerant is added; the video does not cover that diagnosis.
- The speaker refers to his own videos and another linked video for the vacuum and scale process; those resources are not detailed in the transcript.
- Questions can be sent to ScottyKilmer.com, according to the speaker.
Bottom Line
A low-pressure reading with a working compressor usually points to a low refrigerant charge, which can be topped up yourself with gauges, though a proper vacuum-and-scale recharge is the more accurate method.