I just replaced the Evaporator Core. I would like to make sure I have no leak before I put in refrigerant.

I have one of those:


So I connected the yellow to a vacuum pump, blue to load side (the accumulator side) and red to the high side. Then I turn on the pump, open up both red and blue valve, I see the blue gauge drop to -20psi. However, as soon as I close both valves, the -pressure is gone. Blue gauge dorp down to 0psi.

I lock up the yellow tube and reopen the blue valve, it's still 0psi.

Do I have a leak?

If there is one, I assume its probably the pipe connecting the evaporator to the accumulator, but how can I be certain?

 

Pressurize the system with nitrogen, then use a sniffer to find the leak.

 

thanks for the suggestion. However, I don't have access to pressured nitrogen, nor a sniffer.

I used to detect air leak on carburator using compressed air and soap water. Can I do the same thing with compressed air? Or I am introducing water and moisture into the system?

 

Just found the leak.... its the gauge connector
:-@