My wife took 2012 Quest into dealer and we were quoted $1200 in labor to replace AC lines or $600 in labor to repair existing AC lines but he needed more time to determine if the existing lines were repairable. At the bottom of the quote I saw two parts totaling over 1k dollars. I’ve taken it twice before under warranty and they replaced a leaking O-ring the second time. More recently I took it to a local shop and they added Freon which only lasted one season. Can’t afford a 2k dollar fix so I was wondering if anyone’s found a cheaper solution. I’m gonna take it to another place to get another quote

A/c has been leaking for many years since the OEMs began to use o-rings at all the connections to quickly assemble them on the assembly lines. All brands have the trouble, and why one car lasts 10 years with no leaks and the one right next to it on the assembly line leaks all down after only a year. The grooves in the lines come with runout and it affects the sealing as does the actual finish inside the groove as well. If you have lines with rough or wrong size grooves for the rings then every single o-ring you use will likely leak and nothing to be done until the line is changed. Mech in a hurry can take a good sealing one to turn it into a bad one in a second in jamming them back together wrong and roughly. Corrosion on the outside of the lines is no indicator of how bad the grooves can be unless it is very bad. Of course anybody working on the vehicle for pay will say otherwise.

O-ring physical size is a problem too, the OEM ones can sometimes spec oddball thicknesses that are not available over the counter in the limited sets usually sold, they do it to get more returns to dealer to get more work.

Just replaced one of the lines in my Honda and out of 3 connections 1 is leaking. Measured everything and Honda OEM O rings are slightly undersized versus "garden variety" aftermarket O rings. Scumbags all of them.

To OP: If freon lasts 1 year, keep topping up and save the $$

Undersize can be good if the local available one is say an SAE size just slightly bigger. A little harder to connect back up but seals better. It is when the OEM one is slightly bigger than the SAE that the problems really begin. The commonly available one then leaks and cannot be stopped.

Even if tight, the finish alone inside the groove can cause them to not seal if rough enough to not allow the ring to seal right.

Honda is one of the worst, they use screwy o-ring sizes on purpose, I used to have to ring up the four cylinder bikes and bastard sizes every one of them. The carbs gave fits and leaked gallons when fuel turned on after a rebuild, I learned to turn the fuel on, let bowls fill then turn it back off and wait 24 hours for the rings to swell due to fuel exposure (they ALL do it) then fuel back on and zero leaks for the life of the bike after that, at least until you let the carbs dry back out and other problems then as well.

Replaced the line again, this time with the slightly larger generic O-rings. No dice - all are leaking. Will have to put the OEM back in. Maybe size does not always matter. The generic O-rings seemed to be a tad harder and a tad larger than OEM, but only 1 out of 3 OEM leaked, while all 3 generic rings are.

Again just for you.........

'Even if tight, the finish alone inside the groove can cause them to not seal if rough enough to not allow the ring to seal right.'

AND........a physically bigger OD ring is NOT what I'm talking about there, that could be the worst thing you do. Bigger THICKNESS or cross-section instead if cut in two by a razor blade, but still smaller ring like the other.

Stiffer rubber will seal worse in an imperfect groove too. A/C rings are green in color.

Even a correct ring can leak if not lubed to then roll part of the ring over while the rest does not, or it picks up mini-scratches from friction due to no lube. A/C will go right past that.

I have even made my own by installing on a straight piece of steel line with a groove in it, spin it in a drill and lightly sand the OD down using #1000 or finer sandpaper.

I have never had trouble at all ever on sealing o-rings up once I got dead serious about it.

I'd even bet I can refinish/polish the grooves and outer tube to be smoother, food for a future day as I have never done it but with 2-3 ideas in my head how to do that too. Something there will work as there is no reason why it won't. Life in my world outside the box, I don't accept never. There is no rocket science there at all.