How do I know if I need to flush the A/C system?

[ALPO599]

I'm changing the A/C compressor due to it making all kinds of noise and not cooling. Also replacing the Accumulator/dryer and orfice. How can I tell if I need to flush the system before adding the new parts. I keep reading that I have to flush it. I've changed compressors on other vehicles before and never flushed anything. And if I do, what solution/procedure do I use.

edited to say: Forgot to add that this is my 2001 Taurus.

[shorod]

If the compressor was making noise internally, and not just because of a bad clutch or even idler pulley or something in the vicinity and not the compressor, then there is a good chance that garbage has been circulating in the system. If that's the case, it would be a good idea to flush the system to get as much of that garbage as possible out. Sure, it may take a bit more time and cost more, but it's surely less expensive that replacing the compressor again in two years because it the system wasn't flushed.

-Rod

[ALPO599]

Well, Got the compressor and dryer off and also the orfice tube. The orfice tube had a lot of silvery junk on the screen so guess it's all over the system. Tried to dump out the oil from the compressor to check it and nothing came out also nothing from the old dryer. Shouldn't there have been something in them? Any tips on flushing the system? Done radiators but not AC systems. Also there is a muffler like thing between the compressor and dryer. Is it ok to flush that out, too? Sorry for all the questions.

[shorod]

A/C systems are one area that I leave to the professionals. Leak checks and easy repairs I'll do, as well as the simple recharge of a slightly low system. So, I don't know what to suggest for the flush agent/system, and I'm not sure what to tell you about the small canister. I have a visual of what you're talking about, but I've never inquired or researched what the purpose of that gizmo is. Sorry.

-Rod

[ALPO599]

The guy at the parts store said he used to work at a place that did a lot of AC work and they just used that air line antifreeze, that is used for big trucks air brake lines, to flush out ac systems. It's basicly Isoprol (spelling?) alcohol. Says it works really good and evaporates with no residue. Also inexpensive. About $14 for a gallon. Have an air siphon thing, so going to give it a try today and get this thing back together.