VE HVAC System Info

[FalconF16]

Nothing beats some great recommendations.Good stuff

 

[krusing]

Thank you for that comprehensive in put, I do believe that the guy I had been using in the past does a vac/ pressure test to see if it’s holding pressure and it does?? Well according to him? He gets rid of any air in the system before refilling, as for everything else I’m not 100% sure, my engine bay has no oily residue or leaks, honestly the engine bay is clean, I don’t work on the car myself always use to go to holden, it’s only got 140 thou k’s. I’m in Melbourne sth east suburbs so if anyone knows of a great a/c mechanic that would be awesome.

UV Torch is the best tool to find leaks,
I hadn't of found mine if I didn't used the UV Torch.

 

[Lex]

UV Torch is the best tool to find leaks,
I hadn't of found mine if I didn't used the UV Torch.

I'm thinking under the dash? Evaperator?

 

[krusing]

I'm thinking under the dash? Evaperator?

I did think of that,
But I don't like mentioning it,
As it scares people

 

[krusing]

You say South East Suburbs,
Which suburb ?

If your close to me,
Your welcome to bring it around, and I will check it with a UV torch,
but it will need to be after Dusk, for obvious reasons.

 

[GTS98]

bayside radiators in seaford
one of the best guys around
and super honest
took a viva in to get compressor replaced
turned out there was a little bypass valve inside the compressor
$170 later fixed and regassed
next mazda 6
leaking schrader valve $140 fixed and regass

AC mechanics need to be licensed and should follow the industry code of practice which sadly many do not (since simply topping up without checking for leaks isn’t allowed).

As you’ve had continual leaks and top ups, I’d go to someone else for AC service, someone who follows the code. Then get them to look at it.

Best practice is to evacuate the system for a while (as this evaporates any moisture within) and then close the system off and monitor that it can actually hold vacuum (checks for vacuum leaks) before filling with nitrogen to 350psi (?) and monitoring it holds pressure (checks for pressure leaks). Only if vacuum or pressure leaks aren’t occurring should the AC mechanic then fill up with the correct ac gas also toping up with the correct volume and weight of PAG oil if needed.

And here’s where another problem occurs. With leaks that occur quickly, they do take PAG oil out of the system via the leak point (which is why fluro dyes work in finding big leaks). As such, any lost PAG oil must be topped up so that the correct overall volume within the system is maintained. But knowing how much has been lost is time consuming black magic. Having too much oil or too little oil is bad and can ultimately damage the compressor. Best method is to remove the compressor and drain and measure the amount of oil taken out and then factor in how much oil is still within the other parts of the system (the black magic part) so that the corrected amount of oil can put into the compressor. There are charts produced by the manufacturers that estimates the amount of oil that should be added when certain components are replaced.

The fact you’ve had lots to top ups in relatively quick succession makes it all the more difficult as you’ve probably lost an amount of oil that’s difficult to estimate without effort (=cost).

Also I’d guess the engine bay is dirty and oily which may (or may not) make it hard to see the dye glow green under UV light, may be… It could be worth giving the engine bay a really good clean (especially around all AC components including under the car near the HVAC drain vent). Then get the AC looked at by a better AC tech as the ones you’ve gone to are just lazy. (You may want to run this past your new AC mechanic before you clean the engine bay).

I‘d be surprised if no leaks can be found, after evacuating and charging with nitrogen. The leak may be hard to see because of modern packaging and beauty shields and covers in modern cars. But AC guys know this just as the6 know that if they can5 find a leak within the engine bay to push a stick up the HVAC drain tube and check whether the stuff on the stick glows green under UV light. If the slime on the stick glows green, you’ve got an evaporator leak (which is $$$ to fix).

Good luck with finding an honest and decent AC mechanic.

PS: IIRC, all modern vehicle AC systems have a dye pill installed during manufacture. Normally it’s not something that should be added unless the system has leaked heaps. And before it’s added, the leak should be identified and fixed, else it’s just a money grab and risking your compressor in the process (because of associated oil loss as I’ve said).…

Lastly, if the system is opened up to at o sphere for more than 5 or 10 minutes, a new desiccant/filter bag must be installed which is something erase most AC guys don’t do…

Got it booked in Tuesday with another air con shop, told them the issues I’ve been having and to once and for all please find the issue… will post a reply next Tuesday with the outcome, fingers crossed the issue can be found and fixed….

 

[Fu Manchu]

I'm thinking under the dash? Evaperator?

Don’t think that.No. No. Anything but that.

 

[GTS98]

Don’t think that. Anything but that.

Anything but that…. Lol, did a heater core in a vy many years ago now, never ever again…. Wouldn’t pull my dash apart in my ve…

 

[Fu Manchu]

I’ve done a VP. Wasn’t fun then but now I’ve done it a few times, it’s also a good opportunity to improve what Holden did, clean, reseal things.
Getting a HVAC to overhaul first will be advantageous.

 

[GTS98]

I’ve done a VP. Wasn’t fun then but now I’ve done it a few times, it’s also a good opportunity to improve what Holden did, clean, reseal things.
Getting a HVAC to overhaul first will be advantageous.

Yep know the pain. But hey saved a few thousand