Why no Gauge? AC Overcharged?

Is your AC Overcharged? Why not use a low-side gauge to see if your system is charged correctly?  Because low-side gauges do not work on many of today’s vehicles.  Modern A/C systems use a Thermal Expansion Valve (TXV) with a sensor bulb, which can cause inaccurate pressure readings! Check out these testimonials from major retailers and see some of the problems caused by overcharging.

AC Overcharge Testimonial

“I followed the directions exactly and careful to keep it in the “V” so the system would not be overcharged. Initially thought it went well as the AC was now cold. A few hours later I had a completely non-working ac. Like other reviews, the gauge completely inaccurate and I blew out the system. An extremely expensive mistake. Had I read the reviews I wouldn’t have gambled $35 against $2,000 with a 1 in 4 failure rate.” -walmart.com customer review

“My A/c was pretty good, but not quite 100%. I thought maybe I was slightly low so I thought I would try the A/C Pro. I followed the instructions on the can. Now it doesn’t work at all. Gauge reads in correct zone. I get nothing but hot air. Help line was not helpful other than to tell me to take it in to service. Maybe the gauge is faulty, I don’t know. But I just wasted $40 and may have cost myself $500 to replace the A/C.” -walmart.com customer review

“I relied on the gauge and found out the hard way that it is completely off. Defective is the best word to describe it. Might just have been this unit but I over charged the system and it shut down completely. If you charge with this unit alone, make sure you also monitor the air temp inside the car which should be between 40 and 45 degrees F depending on the ambient temp. I had to vacuum out the entire system and recharge it with a set of manifold gauges that I bought to do it right.” -Amazon.com customer review

“I bought AC Pro with built in gauge and followed the instructions to the letter. Ambient temp was 87 degrees F. I set the gauge and turned the AC on max with max fan speed as instructed. Next hooked the line up to the low side service port. Gauge was reading low so I next proceeded to inject refrigerant per the instructions. The gauge reading did not fluctuate that much from what it was originally and I ended up putting the whole can in at which point the AC was not blowing cold any longer indicating I had overfilled the system.” -Advance Auto Parts customer review

“I have been charging AC systems for years. Never had a problem. I charged my 1996 Crown Vic with this 3 days ago, and the compressor suddenly seized up today. Likely cause is overcharging, however I was very careful to keep the charge levels in the green and not tip the can. The only conclusion I can reach is that the gauge itself was not accuratem or the oil was incompatible. Thanks for costing me a thousand bucks.”  -Advance Auto Parts customer review

Testimonials are verbatim as found on retailer websites. Underlines added for emphasis.