Automotive Air Conditioning Information Forum

aerosol wrote: Thu Jun 12, 2025 7:23 pm Refrigerant was put in with dye by auto shop. After 12 days, leak was found at the high side line where it meets the condenser (please see photo below). Could the leak be due to a leaky o-ring? I was told that the leak is likely at the condenser assembly itself instead of the o-ring.

JohnHere wrote: Thu Jun 12, 2025 9:13 pm Using a pair of UV goggles and special light in a darkened garage, if you see traces of dye coming from the condenser, you'll have to replace it, along with the receiver/dryer, which might be integral with the condenser.

Likewise, if you see dye coming from the mating surfaces of the "peanut" connector and condenser, the leak might be from a defective o-ring.

In either case, you'll have to recover the existing refrigerant (if any), evacuate, and recharge the system to the manufacturer's specifications, or have it done by a qualified shop.

Cusser wrote: Fri Jun 13, 2025 6:29 am

aerosol wrote: Thu Jun 12, 2025 7:23 pm Refrigerant was put in with dye by auto shop. After 12 days, leak was found at the high side line where it meets the condenser (please see photo below). Could the leak be due to a leaky o-ring? I was told that the leak is likely at the condenser assembly itself instead of the o-ring.

The AC shop cannot 100% tell whether the O-ring or condenser is bad, and knows that if they replace the condenser and the O-ring that you/customer will have cold air.

The shop doesn't want to gamble with YOUR money that only the O-ring needs to be replaced.

I will say - since I do have my own equipment and do my own labor - that if this was my personal vehicle I would try the replacement O-ring first.

Cusser wrote: Fri Jun 13, 2025 9:29 am The shop has the equipment. I'd ask for a quote to replace the O-ring and replace refrigerant separately, and one if the condenser/drier needs to be replaced. Access to the fitting/O-ring looks straightforward from your photo.

If it really is the condenser leaking, then you'd pay the TOTAL of the two quotes as the refrigerant would need to be removed and replaced a second time. Note that refrigerant removal, evacuation, and replacement is all automated with a special/expensive machine but still would need to be done a second time if the condenser is bad.

johnarden wrote: Sat Jun 21, 2025 5:12 am Yes, it could definitely be a leaky O-ring. O-rings can dry out, crack, or lose their seal over time, especially on older cars like a 2011. That spot where the high-side line meets the condenser is a pretty common place for O-ring failures.

That said, your mechanic might suspect the condenser itself because sometimes the metal around the fitting can develop small cracks or corrosion, which also causes leaks. If the dye is showing up around the fitting but not exactly from the joint, they may think it's coming from the aluminum part of the condenser instead of the O-ring.

Honestly, I’d try replacing the O-ring first — it’s a cheap and easy fix compared to replacing the whole condenser. If that doesn’t solve it, then yeah, unfortunately, you may be looking at replacing the condenser.

Hope that helps! Let us know what you end up doing and if it works out.