Making a Large A/C System Flush Tank On The Cheap

The insides of that tank may not be clean enough for this to work. At least the theory is sound and it will dispense liquid under pressure with inert gas. Be nice. I don't want to have to tell anyone that. Generally speaking, unless I'm in a truly superlative mood, I don't give warnings any longer. I don't claim or happen to know everything. Sometimes I do stupid things. I'm not an HVAC/R "super tech". I'm still fairly new to the field and it's only something I do as a side job.

You may want to watch the video about charging and testing the Allis Chalmers 8070 air conditioner before watching this one:    • Allis-Chalmers 8070 Tractor Air Conditioni...   . The system was prepared and charged with little diagnosis at the request of the tractor's owner, because they needed to put it into service right away and none of the cab windows can be opened.

The Allis-Chalmers 8070 didn't cool all that well right after charging. It was barely adequate and pooped out a week or two later with warm air coming out of the supply vents in the cab. Ambient temperature was about 88°F. At that time I noticed that the suction and discharge lines at the compressor were both hot. The compressor clutch was engaged as it should be. I discovered that one of the replaced Schrader valve cores (high side) was leaking. At that time, I recovered the charge and got two of the 2.7 pounds back, so it certainly should still have been capable of working. I later checked for the presence of a restriction, which I did not find. I then thought the TXV might not be doing its job. We replaced it, and while it helped a little, the system still performed poorly with insufficiently cooled air coming out of the supply vents, slightly low head and high suction pressure. I now believe that perhaps the compressor is possibly leaking from the high pressure side back to the low pressure side (suction).

Soon the system will be thoroughly cleaned before being substantially rebuilt, placed in a deep vacuum and hopefully restored to proper working condition. A "helper" electric fan is also to be installed on the new condenser coil. I don't plan to make a video of all this, as it's just a lot of extra work at a time when it's miserable to be outside for any length of time.

The tanks I've been using come from Flame King (what a great name for refrigerant recovery tanks, no?) and I've been happy with them so far when used to store any of R-12, R-22, R-134a or R-410A. They are available from the following links, which are not affiliate links and might go bad over time:

https://www.amazon.com/Flame-King-Ref...
https://www.ebay.com/itm/111464300700
https://flamekingproducts.com/collect...