Originally Posted by LarryBible

Okay, just fill the compressor with liquid, don't turn it by hand to ensure that it is not liquid locked and crank it up. It's your compressor, so you have all the right in the world to destroy it if you like.

I would say that filling it with oil and not turning it by hand, you would have a chance of NOT liquid locking the compressor. I suggested, as you would find on any a/c web site, that you turn it by hand to ensure no liquid is present to destroy the compressor. I suggested this as a courtesy by sharing my personal experience with you in an effort to save you a compressor. That's what we do here on this site. We try to help each other.

For those who don't believe that we know what we are talking about, they can tell us that we are full of it and do what they like.

As to liquid lock being impossible because of a reed valve, how do you think that the compressor COMPRESSES? The reed valve closes on the compression stroke. With liquid in the cylinder something has got to give. Even if it's the reed valve that gives, you will still have to replace or repair the compressor. We are only trying to tell you how to prevent that.

Originally Posted by Chas H

Your explanation of a reed valve is completely wrong. A reed valve is a one way valve and offers no resistance to flow as the refrigerant is compressed. You don't know what you're talking about.

Originally Posted by brewtoo

Truth is, what you are saying is backward. The valve offers resistance WHILE the refrigerant is being compressed. If there was no resistance as you say, the would be no compression - and we would not call the component a COMPRESSOR. I don't know what we WOULD call it, because it would be useless. Maybe we would call it a door stop or a paper weight.

The way you describe it would be like having the spark plugs fire in the engine while the valves are open, which of course does not happen since if it did, the engine would not run and produce power.

All this is rather obvious to anyone, I would think.

You are just toying with us, right?

Originally Posted by Chas H

Pressure in the high side of an A/C system is not measured in the compressor but considerably upstream from it. That pressure is the result of throttling by the expansion valve.

Originally Posted by brewtoo

OK, got it. It is not the compressor that compresses the gas and forces it through the condenser where in condenses into a liquid.

I have now learned that it is the expansion valve that does the compressing, and not the compressor.

Just curious. When the mixture in the engine is compressed before ignition, is it the muffler that actually does the compressing, through the miracle of back pressure?

Originally Posted by Chas H

An air compressor would be a good comparison. If the outlet of the compressor is not connected to a tank, just venting to the atmosphere, there is very little pressure made.

Originally Posted by brewtoo

I believe the question is about the compressor. Whether it is vented or not is irrelevant. It is still a compressor. The compressor compresses the refrigerant gas in an AC. The evaporator does not compress the refrigerant, it simply meters the (now condensed liquid) compressed refrigerant into the evaporator.

Reminds me of an old saying...

For those who understand, no explanation is necessary.
For those who do not understand, no explanation is possible.

Have a nice day.