can not locate ac freon leak.

[chris989]

Hello all,

1989 v2500,,,5.7

This is my 3rd time trying to find this leak,,, after converting to sanden, the system will pull a vac and hold over night. But when charged it will lose the freon after a week or two.

I then charged the system to 100 psi and it will hold forever. I replaced a suspect oring and charged.. 2 weeks,, low on gas.


It is not charged to 100 psi again,, and it will hold,, but i know it will lose gas afterwards,


Is it possible a leak presents itself when the metal expands or contracts in the evap or condensor due to temperatures??? Any guesses