A/C filling connector test

[chriz1]

Hi, my father took his bmw 1 series into the garage for air con to be emptied and recharged but they said they have found a leak in the connector they used to fill it the guy did show him the part and he said he used some kind of fluid that showed bubbles coming out,
I've just tried to replicate this at home with some water but I'm not getting any bubbles?
Need to check if it is defiantly leaking before I change it as the garage used is good at persuading people in having extra work carried out when not needed!
What's the best way to test?

[Matt Seabrook]

It may have been depressurised so you will not get bubbles out of it. To test the systems integrity you use nitrogen not R134an. You can't leave the nitrogen in the system. If you don't trust the garage get spa second opinion from another. The thing is though if he saw new bubbles be emitted by the component it's leaking.

[chriz1]

Ok
How could I test this valve for leaks would a small amount of water show up the bubbles?

[Matt Seabrook]

Testing with nitrogen is done at 8-10 bar. If you can fill the system with that sort of pressure of nitrogen then go for it. Don't use compressed air!

System running pressure can be 20 bar safety pressure blow off it about 40 bar compressed air and oil will act like a Diesel engine inside your AC system.

Edited by Matt Seabrook on Saturday 10th May 21:44