How to flush an AC system?

[ClassicFordGuy]

Was going to replace the compressor, drier and expansion valve on my girlfriends 96 jetta. I was told even if there is no sign of debris that I needed to flush the system.

Anyone have any tips on how to do this? The only time I've tried flushing a system I had the evaporator out of the car and I emptied an entire arosol can of flush into it before it even dripped out the other side. I just cant imagine that is the most effective way to flush a whole system.

I have a vacuume pump and plenty of compressed air, is there some other way or some other chemical that can be used?

Thanks,

-Rob

[ClassicFordGuy]

Anybody done this?

[K.N.94PSD]

Rob,

The cheapest effective way to flush is to rent a pressurized flush bottle from Auto Zone, the number is 326078 or 91046-A. It's fairly self explanatory, just fill the bottle with a high quality AC solvent, pressurize the bottle with an air compressor and clean dry air, and then stick the nozzle into whatever you're trying to flush and depress trigger. Flush until you don't get any contaminates, and flush some more. Remember, you can't flush through lines with mufflers (they'll have to be replaced) orifice tubes, compressors, accumulator/driers, or certain types of condensers (parallel flow) .
Another option would be to take the vehicle to a good AC shop and have them flush it for you, preferably with a machine in the following article.
A really good article on flushing is as follows;
http://www.autoacforum.com/attachmen...APER%20vs2.pdf

Hope it helps,
K.N.

[444-4D]

This is my favorite way.
Robinair HVAC service tools for Cars and Trucks : Products

This is my least favorite way.
Robinair HVAC service tools for Cars and Trucks : Products