Using R134 to test in an R-12 system

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robmaxfli
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Joined: Fri May 13, 2016 7:07 am

Using R134 to test in an R-12 system

Postby robmaxfli » Fri Jul 14, 2017 10:12 am

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.. :x

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?
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Cusser
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Joined: Sun Apr 24, 2016 6:29 am

Re: Using R134 to test in an R-12 system

Postby Cusser » Fri Jul 14, 2017 11:25 am

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.. :x


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.
robmaxfli
Posts: 22
Joined: Fri May 13, 2016 7:07 am

Re: Using R134 to test in an R-12 system

Postby robmaxfli » Fri Jul 14, 2017 12:08 pm

ok - If I add R134a will that distribute the UV dye that I added (without turning on the compressor)?
thanks
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Cusser
Posts: 258
Joined: Sun Apr 24, 2016 6:29 am

Re: Using R134 to test in an R-12 system

Postby Cusser » Sat Jul 15, 2017 6:01 am

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


Doubtful.

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