A/C question (bleeding a system that may have "leak-stop")

Edit: Called Firestone, and the guy there said it was dye. Was very helpful, and would go there to have it evacuated, but it costs $23 bucks less to refill it and $40 to pull a vacuum to drain it - so it costs $17 more to "reuse" my old R134 instead of just filling it with new. Kinda ridiculous.


I have a '96 with R134a, and I need to drain the system so I can remove my HVAC box to replace the heater core.

I called around some shops, and it looks like it would be more expensive to capture the refrigerant (even when they offer a "credit")than to just vent it.

With that in mind, I started venting...

Rather than being a clean, clear liquid, like I expected, the resulting fluid is yellow and foamy. It reminded me of Great Stuff foam in a can. It's much thinner and evaporates, but it does leave a solid stain behind on a rag.

Does this mean that someone loaded my jeep with leak stop, or is this just dye?

If it is leak-stop, I would be worried that since I will be disconnecting the system and thus introducing moisture and air (I will probably have it open for a couple weeks), the leak-stop stuff that's left in the system will turn to goo and gum up the works.

Should I stop bleeding this myself and take it to a shop? Or am I being paranoid?

Thanks guys!

To answer your original question, what you are dealing with is more than likely a leak detection dye. they are generally yellow to flouresecant green in color to aid in detection by both the human eye and a u/v (black) light style leak detector. As far as whether or not to continue venting I would strongly caution against it. Although r134 is considered safe for the environment the epa still has all sorts of little rules regarding its release, accidental or otherwise, plus its nasty stuff in your eyes, nose and throat. I would pay the little bit of extra money to have the refrigeration recovered properly, and then have the system properly evacuated and recharged post repair. I would also caution against leaving the system open to atmosphere for a couple of weeks. you want to limit the time that air and moisture can spend in your system. I know its probably more of an answer than you were looking for but I hope its helpful.
:repair:

The e-vac is to remove air and moisture so you will still need to have it done before the system will work again.
Oh and there is OIL in the system and that's must be put back too, thats what your seeing most likely.

Hey guys, thanks for the advice. I went back and finished bleeding it myself, and it turns out there really wasn't a whole lot in the system. I very rarely use the A/C, and the last two years I've had to fiddle with the switch to get the A/C to kick on, but it would eventually come on. Based on the amount I released I probably only had ½ lb. ... definitely nowhere near 2lbs.

I didn't even think about oil until I rubbed some of the residue between my fingers - I'm pretty sure that's what it was.

Since I don't use it very often, I'm not keen on the costs - have to replace the expansion valve and drier (and I think there's a hose that needs to be replaced too), and then it's another $130+ to vac and fill the system.

Seems a real waste to spend $200+ to replace $30 worth of r134 all so I can change the $40 heater core. Well, that's not a new complaint for anyone who owns an XJ I guess

Is there any reason I should let a shop do the vac/fill for $140 instead of paying them $30-40 to pull a vacuum, and then going to Autozone for a couple of $15 cans of R134?

When you do get it all apart put some kind of plastic sealing plugs on all the inlets to minimize moisture getting in and working on the system. The shop you use may have the correct sizes laying around, they look like vacum plugs only much bigger, the ones thay may have laying around usually come in on the system parts they get for replacments.