Hey guys, I bought a C5 and am new to car repairs, so I appreciate the help. My AC system is leaking, and after a freon recharge, it stops getting cold within a day or two. I used some UV dye to find where it was leaking, and I noticed that the high-pressure port had some liquid bubbling up with some UV dye. I'm assuming that's refrigerant, but should there be any liquid in the high-pressure pipes? Also, what should I replace to stop this leak? Furthermore, I haven't been able to find any other areas that are leaking, but I feel like the leak is too fast to be just from the high-pressure port. Any help/advice is greatly appreciated

 

Suggest you take the car to an AC specialist…this type of repair is beyond the capabilities of most DIY’ers !!

 

1000% agree. Pay a competent AC Pro.

 

You MAY be Very Lucky. There us no reason that there should be any dye in the high pressure port - so if there is some - it's fairly likely that the High Pressure valve is leaking (I'm assuming that the leak detector was put in through the low pressure port.) The valve stem is similar to the core of a tire valve. Basically you discharge the system, unscrew the stem - and screw in a new stem. Then evacuate and recharge the system.

Unless you have the vacuum pump and charging rig (the tools to required to evacuate and recharge the system) - you're going to be going to a pro who has the capabilities to do the job Make sure the shop you go to has the ability to replace the high pressure valve core - not all shops keep those around.

 

Doesn't the dye circulate completely through the system? If yes, why would not the dye be running past the high pressure valve in the port? Especially if it is leaking like a loose or bad tire valve. Maybe I dont understand the use of the word port? Isn't the port whst holds the valve? Thank you.

 

Moved to C5 Tech for continued discussion.

 

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The dye is normally injected at the low pressure port and does run through the entire sealed system. So - if you have any ability to "see it" at the high pressure port - then the dye has managed to get past the valve that "seals" the high pressure port.

 

It sounds like dye is leaking out of the a/c connection port 'schrader valve' weird needle looking thing, is that correct?

If so first thing I would do is try to tighten it gently. Failing that I suppose it would need to be evacuated and fixed, maybe a new valve installed with a new o-ring if applicable, properly tight.
ON the other hand this type of leak is kind of rare unless the 'port' has not had any CAP on it this entire time and got filthy and ruined from the environment impact.

So to this, take great care with WHERE the leak is, because it may be a tiny CRACK near the valve, and not the valve itself. This is more common of a type of A/C failure line as the aluminum tends to behave as brittle fracture failure due to stress as vibrations over many years. That is the frequent aging failure we expect to see in aluminum where it is thin and stiff and vibratey.

To fix most of these the system needs evacuation. Then the fix is done, either welding or replacement of the part is generally needed. I used to love tig welding up A/C lines for engine swaps 20 years ago. Not hard but you need a welder right. So after the fix, and this the very important essential part, the system needs to be vacuumed fully to remove all water and also ensure it seals up nice and leak free. Getting out water is very important also. I am not an A/C expert by any stretch but I understand the need to do this is essential for longevity. I love to leave the vacuum in the system for a long time to make sure it is not sucking any air. Then, you can fill the system with the correct amount of refrigerant, and the correct amount of oil. Compressors need oil, not just refrigerant.

 

Thank you for the information/advice. It's much appreciated. I don't have much time on my hands right now, and it seems like a complicated system to me, so I think I will take it to a shop to get it done right.