On our trip to KC car show, checking the oil at a gas stop and found freon oil slick all over the pass side of the engine, dripping from rockers etc. huge foamy thick dripping copper color stuff appears to be coming from the copper tube and nut that rest vertically on the front of the a/c suitcase under the coiled up thin copper lines. I almost think loose fitting since the hoses are all new. Anyone ever see that connection all foamy ? Im looking for a dealer or shop to put guages on again and pump up to see if its loose fitting or a hose.. its hot driving without a/c in 90 degree 90% humidity air, :( I will know alot more after a shop sees it under pressure again. darn :(

Is it the bottom connection entering the evaporator (expansion valve) or the top connection (POA) exiting the evaporator? In either case, put a wrench on it and test the fittings to ensure they're tight. Since you indicated new hoses, that's a good bet. Hopefully that's all it is and you can recharge the system and be on your way. Any connection on the system can leak that foamy colored residue as the charge is circulated throughout the system.

If there is that much oil, I'd question if the system was overcharged with oil. I'm not saying that it is or isn't, but it's a valid question to ask of the shop that does your AC work. It's common to put a bit of extra oil charge in if a system has been down for a while, but quite often it's not required and a system that is overcharged with oil will not operate effeciently. I'd rather be a bit overchaged than undercharged though.

For what it's worth, vacuuming a system doesn't draw out an oil charge. Flushing the system is a different matter. I don't recall the exact amount a "dry" A6/R12 system should hold, but it seems like it's in the 11 oz range.

thanks Randy for the info. the Firestone store in KC evacuated the system on sunday. He said it had pretty much full freon pressure and readings but he saw the oil film around the threads as seen in this pic. We decided to replace the o rings at that fitting and recharge again.
( $184 worth of work :( ) It started putting out 40 degree air in a high idle at the shop there and no signs of leaks but only about 10 min. of running there. I paid up and hit the road.. I tolerated the heat for about 30 min. then turned on the a/c and it was working great, very comfy, my thermal gun was showing constant 46 degree air coming out at the vents. On a gas stop in Neb. I looked under the hood and there it was again, foaming at the same dang place. I snapped this pic of it then.
I ran the a/c all the way to Lincoln, popped the hood and same foamy oily stuff at that brass fitting. Left Monday morning for Denver and it foamed all the way but kept blowing cold too. I cant see where else it might be leaking from either. He put in 2.75 lbs of freon r134.
any other ideas? sure is weird.
http://www.brainerd.net/~knudsen/69RS/Misc.Stuff/ACfreonLeak.JPG

Jim;

Looks to be coming from the threaded adaptor or the rear of the Expansion Valve.
Just the smallest amount of oil leaking can really cause a visable foaming around the leak area.
If the Inlet Filter were plugged or restricted you would see the leak at the Inlet and notice the system not working well, depending on how restricted it was.
May just need the adaptor tightened or resealed prior to reinstalling the outlet tube if this an original design valve.
Did the service guy check the connection for corrosion at the fitting or the tube area?
There is also a plugged 'port' in the rear of the valve at the base of the Capillary Servo that I have seen leak but, your leak looks a little lower than that. It would require replacement of the Expansion Valve if it's there. Luckily it is a fairly easy task - if you're a A/C tech...

Can you get a good look at the back of the valve with a mirror and light?

John

thanks John, that is good info. to help troubleshoot it. Im in denver now till friday,then heading back to minn. so Im not going to dig into this till I get home again and have my a/c tech in town go over all the suggestions here. :) muchas gratias

The a/c blew cold all the way home over 1000 miles and condensate drained readily too. But it continued to foam at that expansion valve area. Slick freon oil all over the inner frame area by that valve. yuck
I find newexpansion valves only $49 but wonder if the POA valve should be replaced too? they are $350 but a 'kit' for them is $95, so wondering if I should get the expansion valve first, assuming thats whats leaking, then recharge and test again or just get all new POA or a 'kit for POA', expansion and dryer too. The condensor and all hoses are all new so these are the only old parts left in the system. Comments anyone? :)

As long as the system is going to be open, and if the POA is the only original part left, change it or put in the kit. Before re-charging, you or your AC guy might want to pressure test with nitrogen. 100 psi will do. Use "Snoop" or "Sherlock" or any kind of compressed gas leak detection agent to confirm there are no leaks under pressure. (DO NOT use shop air. You do not want to introduce any more moisture than necessary while the system is open.)

Reason that I say this is because I have seen evacuated systems hold 29" of vacuum for a month, but when under operating pressure they would leak slowly. 6 months later 1/2 the freon is gone. The cause could be as simple as a fitting that is slightly irregular and the O-ring wont seal quite right, to something major as a fracture in a fitting or line somewhere that will expand and leak under pressure. Either may still hold under vacuum.

Many AC techs will disagree with the N2 charge citing as unnecessary labor along with other reasons. But I still am using R12 for my own cars and the stuff is TOO EXPENSIVE to afford any leaks. That procedure has saved me a couple of times finding cracks here or there that would never have been noticed until the freon was gone or by chance found with conventional leak sniffing devices. Good luck with fix....Jb

Unless the expansion valve is cracked or not functioning, I can't see replacing it. Isn't there an o-ring seal? Inspect for nicks in it or the sealing surfaces before replacing any other parts.

It's my understanding that all the POA does is regulate to around 30 psi (or less if you've adjusted it). If it's holding 26-31 psi, I'd leave it in service and focus on the leak source.

The one component that I'd consider changing due to age is the dryer - I'm not sure how the dessicant holds up over time and if it breaks down or not. As far as the other components, I'm a believer of not fixing things that aren't broken. If they're marginal/questionable with reason, or not performing to spec I'd replace, otherwise those $$ could be better spent elsewhere.