I don't know what product the tech used, he just said "fluorescent dye" was added to my system when he topped it off with r-12. Next day I brought it back, and he found the very small leak - said I could use the system until probably end of summer and he would keep an eye on the r12 level whenever I brought it in for service. The fluid in the sight glass was yellow brown after he added the dye. No problems running it during the last couple of weeks.

------------------
JCE
87 300E, 65k miles
Smoke Silver