My air-con has been working fine since I had the compressor replaced last year. Around 4/5 weeks ago it started hissing so thought there might be a leak so got it refilled and it seemed to work but again the hissing has begun. It looks like the compressor is working fine as it seems to hold the pressure OK but it drops down when idle.

 

I used a UV light but can't spot any leaks BUT when I removed the cap to the vale on the large of the two metal pipes I could see the bright liquid and it was very slightly bubbling so it looks like where the valve should reseal when you remove the filling connection it hasn't resealed properly.

 

Anyone experienced this before? I am dreading its the actual valve which looks integral to the pipe so the whole pipe would need replacing as it looks a bit of a nightmare

Is it not a Schrader type valve in there , a tyre valve key would be able to check if its tight enough. There is about 100psi in the system so if its not tight it will  leak

Edited 3 July, 201411 yr by erindad

Ah its one of those. I'm guessing to tighten it properly its going to need a fully empty system so its not got pressure against it.

 

I guess a call to a proper Air Con engineer should get it sorted. Hopefully fix the valve and then refill.