I'm not going to waste my time on your crap. Look it up.

ROTFLMAO

Okay, as you've already pointed out I'm stupid. Stupid people are unable to look things up. So, how about you just give me the quick summary?


Fella' the first time I ever saw a reed valve in a compressor was when I was about 12. I'm now 60 and during that time I've seen way too many of them. So PLEASE, explain to me in fourth grade language so that I can understand. How can you build compression with a reed valve that opens to RELIEVE pressure.

I might be old, but I'm sure that I've not yet seen it all, so enlighten me.

You do not add a full oil charge..
Drain the compressor, measuring what comes out. (write it down).
Drain the dryer, measuring what comes out. (write it down).

Add the two for a total.
I generally add 5 - 10 ML additional for system losses.

WARNING:
The only time you ever add a full oil charge is a totally NEW/virgin system..
A used system distributes oil throughout every component, and you end up with excess oil charge = reduced refrigerent charge.

excess oil charge ac compressor
http://www.google.com/search?hl=en&rls=com.microsoft%3Aen-us&q=excess+oil+charge+ac+compressor.&btnG=Search&aq=f&oq=&aqi=

excess oil ac
http://www.google.com/search?hl=en&rls=com.microsoft%3Aen-us&q=excess+oil+ac&btnG=Search&aq=f&oq=&aqi=

excess oil Air Conditioning
http://www.google.com/search?hl=en&rls=com.microsoft%3Aen-us&q=excess+oil+Air+Conditioning+&btnG=Search&aq=f&oq=&aqi=

Automotive Air Conditioning Systems
http://www.familycar.com/ac1.htm

Aircondition.Com
http://aircondition.com/knowledge_base/Home.html



Have a great day..

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Dude, this thread is getting way messed up. A simple review of compressor operation clearly shows that the presence of liquid in a compressor (whether oil or refrigerant) would damage it in short order: http://www.mistermatic.co.uk/aircon/systems.htm

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However, there is now confussing information on the thread..

From my perspective of doing the job and risking the compressor I am perfectly happy to turn it after I have added the oil that is the question...

I am putting in a new dryer and compressor and just replaced the evaporator!

I flushed the condensor and as many hoses I could get too without disconnecting the evaporator again..

The manual says add 120 mL to the compressor and 10 ml to the dryer which I planned on doing. The big question now is

COULD there be enough oil in the hoses to cause too much oil in the system to be ineffective!

I would appreciate some constructive contributions

I would need some answer pretty quick since I need to get my A/C going to get my wife of my back in this TN heat ...

thanks and cheer up...

Did you flush the evaporator? If not, and you put in the specified amount of oil, then you do indeed have too much oil in the system. The evaporator can trap a good bit of oil.

If I understand you correctly and you added the oil only to the compressor and the filter drier, then you should be able to disconnect the evaporator lines, immediately sealing them so as to minimize the amount of moisture that will reach your new r/d, and then flush the evaporator thoroughly. THEN thoroughly blow out the flushing agent from the evaporator and reconnect the lines.

Assuming that I understand correctly that you flushed everything else, then your oil amount should be okay. Since you added the oil the compressor, the last thing you need to do before evacuation or certainly before starting the system, turn the compressor by hand at least a couple of dozen turns. That much oil in the compressor alone requires you to be careful.

Good luck,

Hi Forum gurus...

Here is how we started... (1995 wagon - E320) I had a leak in the evaporator

- therefore replace the evaporator

then I decided to change the dryer and the compressor before recharging the system.

I read the manual and it instructs us to put 120 mL of oil into the compressor but I was not sure weather the low or high pressure side ... I should have done some homework on how compressors work and then it would have been obvious to add it to the suction (low pressure) port.

Now the confusion started on the forum weather to turn or not to turn the compressor with THAT much oil in it!

Here is what I did...

I filled it with exactly the recommended amount of oil (120 mL) since I had a new evaporator, flushed the system and installed a new dryer (with 10 mL of oil as instructed by the manual).

With the compressor held in one hand I turned the compressor and oil started to come out the other port! I stopped turning and caught the oil dripping out. I added the oil which came out to into the hose connecting to the high pressure port. The oil which came out were about 20 mL. Not a big deal.

I assembled everything evacuated it over night. It pumped down fine and I wait till tomorrow to see if it will hold the vacuum.

So here is how I would answer my original question in retrospect...

- Make sure you flush the system and dry it completely with air...

- Now you can assume you have no oil in the system

- Add 120 mL to the suction side of the compressor...

- get it all connected AND the turn it by hand... a couple of turns to keep the excess oil in the compressor from causing a potential damage

- replace the dryer add oil

- evacuate and then refill

I hope this is helpful to generations to come!

Thanks Forum... there is no need to get aggregated :-)

Cheers

It sounds as if I was not clear about turning the compressor. What I mean when I say that is AFTER everything is all together with the correct oil volume et al, turn the compressor by hand. I did not mean to say to turn the compressor with everything disconnected.

Where are these arrogant people coming from these days? Why do we have to endure it? Too many of them. May be time to leave.

And if it were me, I would put the oil in the dryer rather than the compressor. Adding that much oil to the intake of a compressor makes me nervous...even if it won't hurt a compressor to put a liquid in it.

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2006 Callaway SC560

I replaced the compressor in my '82 380SL about a month ago, and the instructions that came with the new compressor said to pour the entire amount of new oil into the low pressure side of the compressor, then position the compressor so that the nose of the compressor is pointed down and leave it that way for at least 15 min. to ensure that oil gets to the shaft seal, then turn the input shaft at least 15 turns, then install the compressor.
This info is right off the four seasons instructions. Not trying to dispute anyone's instructions here, just providing the manufacturer's instructions. Keep in mind that this is for the older style compressor, and may not apply to the newer style ones.

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'75 280C

The two most important issues are that you have the right quantity of oil in the system AND that there is no liquid in the compressor to cause a lock. To prevent the lock you should ALWAYS turn the compressor by hand before starting the engine. Just do this as a standard practice after major a/c surgery.

Distributing the correct amount of oil throughout the system is good practice and at least a smidgeon the compressor so that it is not bone dry upon startup is also a good idea. Just pay attention to the criteria in the first paragraph and everything lubrication wise should work out okay.

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?

__________________
2012 E350
2006 Callaway SC560

The reed valve offer very little resistance. This practical experience of boudenfj is an example-
"With the compressor held in one hand I turned the compressor and oil started to come out the other port! I stopped turning and caught the oil dripping out. I added the oil which came out to into the hose connecting to the high pressure port." The poster was able to pump oil through the compressor by the hand. That would not be possible if the commpressor were bulig prssure internally.
If you've ever had a compressor apart, you would know the reed valves are made of thin material and could not be cause of any high pressure.
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.

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?

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2012 E350
2006 Callaway SC560

An internal combustion engine is not an A/C compressor. Please start a new thread for those questions.
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. Connecting the compressor to a tank causes pressure to build. If we then connect an air hose to the tank and a blow-off nozzle, representing the expansion valve, we have cooled air-due to de-compression.
I hope you do better with the above explaination, because so far you have mis-read my previous post, and you have learned nothing.