can not locate freon leak

[chris989]

Hello all,

Converted the R4 to a sanden. The R4 pancake always leaked slow.. First charge with the sanden, (pulled a vacuum sat overnight with no loss) i loss the freon.

Second time,, I charged the system with 125 PSI of air and thought i found an o-ring as the culprit. changed oring,, charged to 125 psi, sat 2 days, no loss. Flushed, vac'd, charged and still losing freon.

I though,, service valve but i can sniff and soap them with no leak.

Any Ideas???? 134 runs at +200 psi so maybe a nitrogen charge to find it?


Last year,, i was loosing coolant, pressure tested and could not find it,, pulled the heated core before a big trop and sure enough, a green stain was on the core.. never smelled it, never showed up testing. I am wondering if it is something like that?


Thanks
Chris