Refrigerant R134a

[Dougflas]

Yes, I have a Sun recycler.

[wptski]

Yes, I have a Sun recycler.

I hardly do enough to warrant something like that.

[Auto Engineer]

I spoke with the AC engineer at work today who repairs our garage equipment, I asked about the filtering of refrigerant in these refrigerant management stations and he advised that the new machines, mine is about 12 months old, have a built in filtration system, he said what happens is you recover the refrigerant from the vehicle as normal, ideally you would check the refrigerant is recoverable using a refrigerant analyzer before recovering using the refrigerant management station, then if recoverable the refrigerant management station would recover the refrigerant and filter it before passing it into the cylinder that stores refrigerant inside the management station. The recovered refrigerant then can be reused in the same vehicle or any other vehicle that uses the same refrigerant. The RMS LCD shows the amount of refrigerant removed, in this current vehicle 1060 grams was recovered and the manufacturer advises 700 grams should be installed only, so I don't know what effect or damage that could cause in the cars AC system?

The fixed orifice tube when removed had what appeared to be a film of black liquid and some traces of silver particles around the gauze of the orifice tube. I am left wondering if this contamination is from the descant of the receiver dryer and the alloy components or an internal fault in the compressor?

The evaporator some while back produced a very strong pungent smell probably just before the complete failure of the AC system, so I am thinking I should completely remove the evaporator to fully inspect it and clean it if possible?

I'm open to views on this problem.

[GM Tech]

Pungent smell is usually flushing agent that never got removed fro the system-- which is a degreaser and totally detrimental to the system-- this is why I never put anything in the system other than oil or refrigerant-- If I flush, I use refrigerant flushing adapters on my recovery machine.

[Auto Engineer]

-- If I flush, I use refrigerant flushing adapters on my recovery machine.

Very interesting, I bought a flushing kit that came with a cylinder including high and low pressure connections, I have never used it to date as I am unsure how it works in conjunction with my Refrigerant Management Station [RMS], I bought them both separately. Having read the section of the forum on here regarding pulsating flushing I can understand now why normal flushing is of no use to contaminated systems whereby components have failed, although flushing as a system cleanup when servicing a system I would have thought is OK.

I also have another query, when using compressed nitrogen for cleaning and drying out an AC system, how long and at what pressure should the nitrogen be used at?