Liquid r134a charge into low side while running

How bad? How soon will I know if it resulted in a problem and how long before I can be relatively confident it didn’t? Was definitely a little low, but working before adding it, and seemed fine afterward, but I only ran it for about 15 mins total last night. Would any compressor damage be immediately obvious?

Introducing liquid refrigerant into the low side can slug the compressor.

The compressor was designed to compress a gas.

The compressor can’t compress a liquid.

Wait and see if the compressor starts making noise.



Yeah, I know all of those things. That is why I asked the question. Was hoping for a more useful answer than, “wait and see” since that is going to happen by default and goes without saying.

What else ya gonna do?



If you knew all those things, why did you do something you knew might damage the compressor?

Talk about shooting the messenger.


That’s a good sign. If you added it slowly enough, it would be mostly vapor before reaching the compressor.

Since you are already in “wait and see” why even ask

1 Like

If charging into a receiver -drier the liquid would almost certainly be vaporized before reaching the compressor. And My best guess is that the Chevrolet Cavalier had a receiver drier. When the low side port is on or near the compressor a problem is likely though.

I’ve never seen a receiver/drier on the low pressure side on an AC system.


The service port is about 2 feet from the compressor, where I live there is enough under hood heat to boil off the liquid before it enters the compressor.

That would be the accumulator on this car.

Yes, @Nevada_545, and excuse me @Tester, the car’s drier is called an accumulator. And the charging port is on it.

What’s the recommended alternative? Charging the system with the car not running or into the high side? You don’t want try to charge into the high side while running with any normally available equipment.
The gauge set valves allows the charging flow to be metered out at a slow rate so it can vaporize as it enters the system, are we referring to just spinning the valve wide open instead of just slightly cracking it open to allow the refrigerant to flow?