Engine Size: 4cyl
Refrigerant Type: 134A
Ambient Temp: 97
I reviewed your FLUSHING TECHNICAL PAPER vs2. That is quite a thorough and straightforward paper. Thank you very much for posting it! I am looking forward to this additional forum.
Anyhow, a few questions came to mind while reading it.
When I open my system up (this is a 95 4cyl Camry) what will I visually see to determine that I did or did not have a case of catastrophic internal compressor failure? Am I looking for pieces the size of a BB or a grain of sand? One or dozens of pieces? If I cut open the drier/receiver and it looks "clean" am I reasonably confident that particles didn't migrate from the suction side back to the evaporator?
You mentioned that it would be important to "quickly" flush out any systems that might have had sealer added to them. Does this mean in 10 minute or (hopefully) 10 hours? How quick is "quick"? I bought my car used so I have no idea if this was done or not. Are there any clues to look for or tests to make? (Could I put a clear tube on one of the Schroeder valves and leak some refrigerant into it and see a crust form or something? How long would I need to wait before I saw a change?)
While I really like your pulsating technique I don't believe that I will be able to afford it at this time. Can you tell me if it would hurt the evaporator or the condenser to fill them with lacquer thinner and let them sit overnight in order to more thoroughly dissolve any hardened oils? I figured that I could lay them flat outside and agitate them every now and then and then blow dry and follow up with a quart of Four Seasons' DURA II.
Thanks for the comments on the FLUSHING TECHNICAL PAPER, and thank you for the questions.
Understanding that many different and unique things can occur with every failure, is why we say you must be like a "crime scene investigator". When analyzing such a failure it is important to understand where the debris issues are, how the debris entered the component, and the best strategies to employ to get all the waste oils and any debris out. You will possibly find debris of any and all sizes and quantities.
When a compressor fails internally, it will often go out chewing itself up. Most of the metal debris generated will be found at the inlet of the condenser (many act like a 600 micron primary filter). To analyze such a failure, once the system is opened, you can back blow the condenser with compressed air while holding a clean rag at the inlet. The inlet chamber of the condenser is the primary place you will find larger debris indicating internal compressor failure. This debris can range from a lot of filings to chunks so big that boggles the mind how it can even get in there. If there is nothing but oil, that looks fairly clean, with maybe just a trace of metal wear (few sparkles of metal debris), the compressor may still be damaged internally, it just did not chew itself up and fill the system with metal debris.
If the compressor rapidly explodes internally or externally, where rapid Hi/Low pressure equalization occurs, chunks of debris can back up the suction line (TXV system only) into the evaporator (this is a unique and rare phenomenon, but it can happen). Cutting open the receiver/dryer will not tell you much because the condenser acts as a primary filter before it gets to this device; and in such a rare case where debris backs up the suction line, it is usually large pieces that do not enter or pass through the evaporator. Such a failure would probably be seen at the condenser inlet as a small quantity of larger pieces of debris with little fines (evidence of big damage without slow grinding).
Sealers is a big can of worms. They come in all colors and all different types of formulas with claims of impossible feats by the use of mysterious technologies. Basically if it has sealer in it, your system is essentially done, it may require a total system replacement. There are no standard practices for identification, removal, and recovery of a system with this stuff in it because standard practices warn against and do not recommend the use of "magic in a can" over a proper system repair. If you are extremely concerned about this, there are some professional (sealer) identifiers; and maybe it would pay to have a pro analyze before you disassemble so you know what you are dealing with.
Although "leak some refrigerant" is not legal or recommended, it is a common practice to Ã¢ÂÂspritzÃ¢ÂÂ (release) a little refrigerant to see and feel what the oils are like. This is usually done by the experienced tech who can read something in what he sees from his years of looking at systems. Oil colors we see are Black that would be bad burnt, gray would be old & tired with maybe metal fines, and we have seen a milky tan color that did set up or begin to congeal when introduced to air; this would be sealer. You could try your test, but I don't know if it will give you any accurate answer. How long? I don't even think the makers of this stuff can answer that. This is why HECAT says "if you have a chance to save the system from this stuff, you must be ready to flush as soon as you open the system".
Lacquer thinner is very aggressive and flammable cleaner made up of various levels of left over and non conforming petroleum distillate solvents. This stuff varies a lot from batch to batch and would possibly be harmful to any soft seals or hoses. If you are using this on the metal components only, it will probably be OK. Shaking it when out of the car is a similar concept of adding agitation (energy) as our Pulsating equipment will do to an installed component; and the air purging dry is very critical. Following up with the Dura II (HFC-4310me) may not be necessary but will not hurt, just be sure to blow dry after this stuff too. Then follow the "Pop" test procedure as outlined in the FLUSHING TECHNICAL PAPER, to confirm the component is clean and dry before beginning to reassemble.
Good luck and keep us informed of your progress.
is all-purpose thinner ok for flushing?
I should have included more examples in the following statement such as mineral spirits, white solvents, stoddard solvents, and "thinners" in general.
"Lacquer thinner is very aggressive and flammable cleaner made up of various levels of left over and non conforming petroleum distillate solvents. This stuff varies a lot from batch to batch and would possibly be harmful to any soft seals or hoses. If you are using this on the metal components only, it will probably be OK."
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