Flushing Debris from AC system/ How?
 

My compressor blew up and I suspect it clogged up my system somewhere. I am changing it and the rec.dryer and the exansion valve. (got em from Phil in PartsShop)

Q. How does one 'flush out' or otherwise clean the other debris out form the system.

The condensor, in particular must be full of pieces as its the next stop from the compressor.

Thanks folks

The basic approach is to propel a solvent throught the system using compressed air. There are a couple of approaches to doing so.

The most elegant is to purchase a flush gun from a supplier such as acsource.com. Fill it with your preferred solvent - mineral spirits or lacquer thinner are two reasonable choices - pressurize it with compressed air, and blast the solvent through the condenser.

An alternative is to first introduce the solvent into the component being flushed using a suitable tool - a turkey baster or some such. Then use a blow gun attached to your air compressor to push the solvent through.

Lastly, you can purchase aerosol cans of flush from suppliers such as acsource.com. Again, you'll need compressed air to get all the flushing agent out of the component.

You don't need a big air compressor to do amateur a/c repair. A small 120v unit and blow gun can be purchased from Home Depot or similar stores for ~$150. Of course, something in that price range won't run any air tools, but it will fix your a/c and pump up your tires...

JC offered a very good list of alternatives. I recommend using the first alternative because it forces solvent through each component while atomized in the compressed air.

You will disconnect every component in order to flush it and IT IS VERY IMPORTANT to completely and thoroughly blow out the solvent before reassembly. At the time of reassembly, replace all orings and use the glandular sealant on them, which is a stringy grease sort of lubricant.

Also, if you want to really be thorough, find an auto air conditioning supply house and get a suction side filter, install this in the suction line just before entry to the compressor. This will catch any contaminants that you may miss before the reach and destroy your new compressor. If you install the suction side filter, you don't need to be as thorough with your flushing.

Also make sure you use a fresh filter-drier.

Good luck,

Thanks fellas
 

Since posting, I have surfed around and found a good link back in our archive on this site.

www.acsource.com has good tech chat. Here's a piece:

Well you are not flushing the entire system, just the condenser and evaporator. You cannot flush the compressor the accumulator, the drier, or any mufflers. Hoses can be flushed but there is some speculation that mineral oil forms a barrier in rubber hoses. Flushing the condenser is easy because you can remove it, pour in some flush in one end and blow air through it to force it out. the evaporator is the hardest because it is embedded in the dash. Typically you use a flush bottle which is a cannister you fill up with flush solvent and pressurize with air. It forces the solvent into the evaporator, you follow up with compressed air to blow out as much as possible. As you are forcing in compressd air you put your finger over the outlet and do a what thay call "pop and blow", it helps build up pressure to remove more solvent.

For the compressor you remove it from the car and place it upside down on a bench and let gravity remove as much oil as possible. Then you pour in clean oil and turn the hub by hand until the oil begins to come out, repeat this until the oil comes out clean.

The system is assembled with a new accumulator/drier, new O rings and a vacuum pulled to remove moisture and flush remaining in the system.

Hope this helps......


NEXT QUESTION:
Does the 190E have any in-line filters other than the rec/dryer?

I did this on a Ford truck A/C years ago. Found a unit in a junk yard and put it in my truck. I can't remember the name of the stuff but I remember it came in areosol cans and I used two. After blowing it out with DRY shop air, installing new dryer and evaporator valve, it worked great. The unit had been sitting dormant for years. I was a little surprized that it even worked. :cool:

JC/Larry:

Very good post! Thanks for the useful information.
May be headed in this direction soon.

Keep in mind that this process takes the oil in the system with it and must be replaced before charging.

Low-Side, In-Line Filter/ Where? How?
 

Thanks for the great input folks.

I going to get into dismantling the system to flush out the old oil & debris. Several responses (both here and on the Porsche "rennlist") suggested installing a low side inline filter to catch any stuff I dont get out with the flushing.

Any thoughts on getting the filter? Is it a bolt in thing or will I have to bring thel ow side line to someone who makes hoses & high pressure lines and fit some threaded ends on?