Anybody had problems clearing out contaminants in the system- this one is fighting us at every turn. Accumulator replaced, evaporator removed and flushed , all lines flushed , condenser checked for restrictions . Are the any other traps ; the old accumulator had a removable orifice tube but the new style is sealed.
I had to resort to a hvac filter (from a commercial supplier) one time for the same reason. I paralleled two just for the sake of not having to change it. After a couple seasons I took them out and no more problems. I believe the contamination was from an improper charge and repair from a year before I saw it.
Are you back-flushing with the citrus smelling cleaner. It helps to loosen the PAG oil to release debris. What type of condenser and evaporator do you have. Some are flat tubes that are actually bundles of tubes. Those things are notorious for trapping garbage. If you got the round tubes, you should be ok. Good luck.
Air con update ; after many hours of careful inspection , removal, and replacement of the most likely items to create problems the system now preforms as it should have after the first attempt. Maybe a line had disintegrated inside and was blocking the system upon charging, as it seemed to vac down correctly . When the compressor failed it was the steel reeds that entered the system and they may have lodged into the flexible discharge line. Luckily it was our own machine and we could spend time to sort it.
Patience, perseverance and the exact combination of curse words and threats. Works everytime. Glad you found it, now, how exactly did you find it?
The worst I ever came across was a White GMC truck. While flushing the lines, evaporator and condenser black stuff just never went away. Replaced the lines but it continued. The evaporator finely cleared out but the condenser never did. It must have had rubber hose particals cooked into it. Probably spent 8 hours on the flushing program. This one had the round tubes. Glad you have yours worked out and for sharing.
Its probably not the correct thing to do but have had good luck preflushing really contaminated systems with brake parts cleaner first ,then using the ac flush last as it seems no one ever stocks more then a gallon of the stuff. As far as i know all the systems i did that to are still working fine
Parallel flow condensers can not be flushed adequately. They must be replaced.
Try telling owner operators that after you have the system apart and found a failure and they are late picking up there next load , stuff like that is why i started the brake clean method flushing both directions till clean then hit it with the ac flush , they were warned and was noted on work order, service writer made them read it before they signed.
Cover 6 on every ticket.
Some A/C snap on, handle squeezes together and locks not the tool company, will go right on a can of brake cleaner.