Went to job today with new coil, for a/h only months old, Iam going to replace the outdoor heat pump only 6-7 years, cut tubing pull out indoor coil open liq. line where FCCV is, the bullet orifice) is cover is green slime now its startinting to get like hard gunk, I finasllit get orifice out, cant see thru it, thrn screeen completely filled with green slime could even see teh screen, the compressor is a recip. I call owner of building 30-40 units, everything you work on ends up opening a can of worms, everything been hacked from installs 20 years ago, so heres where Iam at, Iam trying to get in touch with him hes out of country for 2-3 weeks, always is, I have to tell him (he ok'd new outdoor heat pump, I bought new inndoor coil with new orice and 90deg. pc. the piping when I cut it open inside to remove old coil has some green on inside of pipe not much, most came from when I cut tubing outdoor mostly suction line, when I took apaert the 90deg. bend fitting where orifice and screen are alot of sh*t in there. to run new tubing the air handler is on first floor, total tubing avout 6-8 feet, 3 feet of it is in behind closet sheetrock wall, a/h would have to be removed, sheeetrock wall cut opened, electrician probably. run new tubing, replce rock, replace outdoor heat pump, and indoor coil, maintenance guy doesnt want to open up wall says its not his job, its mine ($100/hr. mr $18/hr. him I dont want to, the owner just wants to replace indoor coil, outdoor h/p, cut piping to wall replace that small portion and leave the old contaminated tubing in wall, I was going to put driers on, like I said there would only be 3-4 feet of old contanimated tubing, he wants driers and come back in a month and remove, I still think the unit wont last, maybee I tell the owner 1-month, maybee 5-years, replace it alll, he doesnt wabnt to hear about tunning all new tubiung, removing a/h and cutting rock to put in new tubing, he crazy
The Trane R22 systems use yellow mineral oil. The condition you are describing sounds like a variation of "green slime" which only occurs with Copeland scroll compressors using white mineral oil.
I am not that familiar with the Trane compressors, but if they use yellow mineral oil, overheat while contaminated with air/moisture etc. drawn into the system due to a leak on the low side of the system, then you can certainly get a reaction that will cook that oil/noncondensible mixture into an acidic goo.
In Bristol and Tecumseh compressors it is usually pretty darned black. The green coloration is from the oxidation of the copper components in the system no matter what system it is.
Either way, if it is thick and stinky the system is trash. Linesets, coil, outdoor unit; all have to go.