Automotive Air Conditioning Information Forum

I've got all new AC components in my 1992 Buick - nothing reused. I hooked everything back together and pulled a vacuum but it will not hold overnight. I have already added R12 Mineral oil and UV Dye into the system. I have R12 that I want to recharge with eventually.

I then used plain shop air to pressurize the system up to 80 psi - then I used soapy water on all of the connections to see if they would bubble up....I can't find a leak..

Can I use R134 to leak test with even though I have Mineral oil in the system? as long as I don't turn on the compressor?

robmaxfli wrote:I then used plain shop air to pressurize the system up to 80 psi - then I used soapy water on all of the connections to see if they would bubble up....I can't find a leak..

Not so good - most shop air contains some moisture, not good for the drier pellets !!!

robmaxfli wrote:Can I use R134 to leak test with even though I have Mineral oil in the system? as long as I don't turn on the compressor?

Yes. The advantage of R134a over dry nitrogen is that R134a responds with electronic detectors.

ok - If I add R134a will that distribute the UV dye that I added (without turning on the compressor)?
thanks

robmaxfli wrote:ok - If I add R134a will that distribute the UV dye that I added (without turning on the compressor)?
thanks

Doubtful.