Car Air Con

[Damian]

Seems Damian’s tested with pressure.

It was tested with both, vacuum and pressure, both of which had to hold their test value for a specified time otherwise the machine shut down and sounded an alarm and a flashing red light.

 

[Jcloughie]

It was tested with both, vacuum and pressure, both of which had to hold their test value for a specified time otherwise the machine shut down and sounded an alarm and a flashing red light.

It could well be that my ATS test did also, I did not watch and they were not forthcoming. Nevertheless, I think they did a proper job. The diagnostics I posted earlier, did not show that. I only got the diagnostic printout because I specifically asked for it.
I wonder if yours was pressure tested with nitrogen.

John

 

[otherclive]

A bit more research and I find that pressure testing is recommended by some. But using nitrogen. As in this extract.

In the book, I describe using nitrogen to pressure-test an empty air conditioning system in order to find leaks. I’ve long been surprised that this is not a widely used technique. Most of what you read online says either: A) You find leaks with a vacuum pump during the evacuation phase; B) If you previously filled the system with oil with dye in it, and it worked for a while but now is leaking, you find leaks by using an ultra-violet light to look for the dye; or C) You find leaks by using a chemical sniffer on a system that still has refrigerant in it.

From here.

It might be that places like ATS test with a vacuum simply because they have to vacuum it out anyway. Or, more likely in my opinion, that testing under pressure with air may introduce moisture and/or dust which is counter productive. And using nitrogen increases the complexity and cost.

Its all academic anyway. I was just being inquisitive.

Seems Damian’s tested with pressure.


John

Thank you it seems that you have read the same reference as me, in my above post I wrote that some favour a pressure test after vacuum evacuation and CO2 or Nitrogen, or even an inert welding gas can be used. No risk really of introducing moisture as those gases can be obtained “ dry”.

 

[Kevin M]

I’ve been watching this thread and been quite envious of you folk just having the systems regassed and all sorted.
We have been having a saga with ours since having it regassed a month ago.
On the original test it showed an empty system. Charged up with the inert gas showed a leak. My friend the engineer had a few thoughts on a repair, we did one and tested it. All good. Gassed up and icy cold.
A day later, tell tale signs of the dye showed a leak!
Another repair, another regards and...leak again.
We decided to leave it for a few days and look at options (he is an air con tech btw)
I had a good read up and found an online company selling stuff and took the decision to by an 8mm stainless inline compression joint and some air con specific locktite.
I cut the damaged item out, cleaned up and fitted the joint.
Andy turned up yesterday, regassed and fingers crossed seems to be fine.
Interestingly, when doing the regas, the cylinder is placed upside down, the reason for this is so they can accurately measure the ‘liquid’ used in the regas (if that makes sense)

Kev

 

[Jcloughie]

I’ve been watching this thread and been quite envious of you folk just having the systems regassed and all sorted.
We have been having a saga with ours since having it regassed a month ago.
On the original test it showed an empty system. Charged up with the inert gas showed a leak. My friend the engineer had a few thoughts on a repair, we did one and tested it. All good. Gassed up and icy cold.
A day later, tell tale signs of the dye showed a leak!
Another repair, another regards and...leak again.
We decided to leave it for a few days and look at options (he is an air con tech btw)
I had a good read up and found an online company selling stuff and took the decision to by an 8mm stainless inline compression joint and some air con specific locktite.
I cut the damaged item out, cleaned up and fitted the joint.
Andy turned up yesterday, regassed and fingers crossed seems to be fine.
Interestingly, when doing the regas, the cylinder is placed upside down, the reason for this is so they can accurately measure the ‘liquid’ used in the regas (if that makes sense)

Kev

Best of luck this time, fingers crossed. 🙏.


John

 

[Raywood]

Not sure if the air con works on ours as we very rarely use it. I never pay for work on it and do not accept the dealers offer to work on it when the car is serviced.