Why is my compressor pulling into a vacuum?

It sounds like a faulty expansion block as it’s common for the low side to go into vacuum when it fails. It’s unusual for the 10PA series Denso compressors to shed debris into the system so once you pull the drier and expansion, check the lines for any sign for debris.

Can you pull a vacuum on a compressor?

Some techs say that pulling a vacuum below 250 microns can damage the compressor oil. I’ve done extensive research and spoken to many experts and have seen no evidence that evacuation below 250 microns causes any issues with POE or mineral oil.

How long does it take to pull a vacuum on an AC unit?

With a vacuum pump connected to both, low and high air conditioning system sides pull a deep vacuum for at least 5-45 minutes. A vacuum of about 500 microns or 29.92 hg gauge pressure is needed for removing any moisture that may have entered the system along with the non-condensable gases while it was open.

How long should you pull a vacuum on a normal compressor change out?

Isolate the vacuum rig with the core tools and allow the system to stand for 15 to 30 minutes. If the micron level does not rise above 500 microns the evacuation is complete.

What happens when a / C low side pulls into vacuum?

A/C compressor goes on and low side goes into vacuum. Compressor turns off then slowly goes back to about 30 psi. High side stays around 100 to 120 psi. Expansion valve and compressor already replaced. I’m guessing there is a restrict somewhere. have the same problem? Yes, there is a restriction on the low side. Did you use a new expansion valve?

What’s the difference between high and low A / C compressors?

A/C compressor goes on and low side goes into vacuum. Compressor turns off then slowly goes back to about 30 psi. High side stays around 100 to 120 psi. Expansion valve and compressor already replaced.

What should the pressure be on the low side of the AC?

The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. But if you see the AC low side high, high side low, such as the low side is 100 and the high side is 150, there might be problems with any of the inner components.

Why does my a / C compressor pull on low side?

Over 35psi (at speed) can mean a stuck open TXV or compressor valve issue. High Gauge is based on ambient temp. Basic formula is Ambient X 2.45 (min) Ambiant X 2.5 + 50 (max). 100 degree ambient = 245 – 300 psi. Humidity will effect it. high humidity will raise the range and low will drop a little.

A/C compressor goes on and low side goes into vacuum. Compressor turns off then slowly goes back to about 30 psi. High side stays around 100 to 120 psi. Expansion valve and compressor already replaced. I’m guessing there is a restrict somewhere. have the same problem? Yes, there is a restriction on the low side. Did you use a new expansion valve?

A/C compressor goes on and low side goes into vacuum. Compressor turns off then slowly goes back to about 30 psi. High side stays around 100 to 120 psi. Expansion valve and compressor already replaced.

The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. But if you see the AC low side high, high side low, such as the low side is 100 and the high side is 150, there might be problems with any of the inner components.

Over 35psi (at speed) can mean a stuck open TXV or compressor valve issue. High Gauge is based on ambient temp. Basic formula is Ambient X 2.45 (min) Ambiant X 2.5 + 50 (max). 100 degree ambient = 245 – 300 psi. Humidity will effect it. high humidity will raise the range and low will drop a little.