Conversion to Freeze-12

[Kurbycar32]

Tip: the refrigerant is actually more heavy than air so you will find the dye under the leak, not over. make sure to check inside the dash too, you could be leaking at the evaporator

[FastWoman]

Then the dye comes out as a gas? I thought it was in the oil.

[Kurbycar32]

the dye colors the refrigerant so when it leaks out you can see it with the UV light. so yes you are looking for a leaking gas, not an oil

[ZCurves]

Sorry Sarah, just now seeing the responses, I believe that KurbyCar32 hit it spot on. After you repair whatever is exposed by the dye, make sure to clean the area with Brake Cleaner and then something soapy to remove the dye -This way you will get a 'Clean Slate' for future leak detection.

There is also the possibility of borrowing a Halogen Leak Detector to check for leaks. I say borrow, because these dudes are mucho $$$ to buy for the casual user. Just thinkin.....

[FastWoman]

There is also the possibility of borrowing a Halogen Leak Detector to check for leaks. I say borrow, because these dudes are mucho $$$ to buy for the casual user. Just thinkin.....

It might be possible to borrow one (with a big deposit) from a local auto parts store. I'll check into it.

[Willoughby Z]

Harbor Freight- $74.99

[hr369]

is there oil around the front of your a/c compressor? if so, the front seal is leaking. another place that leaks is the high and low side charge ports.

and lastly the rubber hoses can leak but those first 2 are the most common places to leak. you cannot just keep filling with freon though. whenever

freon escapes it takes oil with it so you're probably running low on oil. ive replaced valve cores before and they've still leaked. probably the seat is

bad but not sure. maybe just cheapo replacements. one quick fix is to get some r134 charge port fittings and remove the cores if they have any.

then find a bolt that will thread into the top of the r134 fitting, most are threaded on the inside. i use teflon tape on the bolt thread too. then i screw the retrofit fitting over the top of my r12 charge ports and it seals pretty good. start the car and test with soap and water from a spray bottle. at the very least put a few oz. of oil in before you top off.

[FastWoman]

Thanks, hr369! I'll look for those trouble spots. My one known leak is on the high side connection to the evaporator assembly at the firewall. It's a bit oily there. The compressor looks pretty clean. Adding oil sounds prudent.

I'm afraid I've been slow to get to this repair. Perhaps I'll be able to locate that "round tuit" when the weather gets warmer.

[FastWoman]

Update: I finally got more motivated with the warm weather, and my A/C is blowing cold again.

I found the leak. The flare fitting on the high side of the evaporator coil (at the firewall) had gotten loose, so I tightened it (and also the low-side fitting).

Now here's a clever way to reclaim your freon without a fancy freon reclaiming machine. You'll need an empty freon can that you've saved back: First, hook up your empty can to the center (yellow) hose of your manifold. Then evacuate it through either the high or low side line. Close your valves, and then hook up your H and L lines to the A/C. Purge the air from the lines at the manifold fitting. Then tighten the fittings, and open the valves. Now put the empty freon can in an ice bath to lower the vapor pressure. What's left of your freon will slowly condense into the can. This will take quite a while, but the operating principle is the same as that of a heat pipe. When you're finished, there will be no liquid freon left in your system. Obviously this won't work if you start with more than a pound of freon in your system.

So with an empty system, I then evacuated, let stand for 30 min, and observed no change in vacuum. I then introduced 2 oz of mineral oil and dye. Here's some helpful info in that regard:

R12 refrigerant oil (rather viscous, dehydrated mineral oil) is REALLY hard to find. There are mail order sources, and I suppose you could buy it with the requisite licenses at a refrigeration company, but there's still one source where everyday people can just go and buy the stuff locally -- NAPA. It's a stock item there. When I asked the guy at the counter for a bottle of the stuff, he said he didn't think he would have any, but he went into the back and surfaced with a dusty 1 qt. white plastic bottle that had turned yellow over the years. The total with tax was $10.15.

Getting it into the system can also be challenging. In the good old days, we'd just buy a 2 oz can of the oil, loaded with a bit of R12, and shoot it in. You can do that with 134a, but not with R12. Our stuff just comes in a bottle. So what you do is use one of those precious empty freon cans that you've saves, patting yourself on the back that you're the sort of pack rat who never throws anything out. You cut it in half, making a cup with a fitting on the bottom. Pour in your oil, and suck it right into the evacuated system. The easiest way to do this is to evacuate via a hose directly from the pump to the low side. Then connect the high side hose to the manifold and the yellow line to the can. BTW, it flows slowly into the vacuum, being rather viscous. Now change around the fittings, evacuate again via the yellow line, and charge the system. You'll get just a bit of oil back into the vacuum pump. (Mine fluoresces yellow now!) FAIW, I think there's such thing as an oil syringe, but I couldn't find one.

Anyway, with luck my system is now tight and will not leak my precious R12. And I'll be cruising the Colonial Parkway in cooooool comfort.

Edited May 20, 2012 by FastWoman

[ZCurves]

Congrats! That is great news! Ten years ago I bought a AC Oil Injector that allows just about any liquid to be added to the AC system. The tool holds approx. 2 oz and a weee bit of dye.

These cost about $30

BTW: I am jealous about your cruising the Colonial Parkway....nice.

Edited May 22, 2012 by ZCurves

[FastWoman]

Yeah, I could have used one of those! Harbor Freight? (I didn't look there.)

The Colonial Parkway is great, but so are parts of Texas. Brenham in the springtime is one of my favorite drives. One particular drive through the Brenham area was the closest thing I've ever had to a religious experience.

[sblake01]

Sarah, are you talking about ester oil? If so, it's really not that dificult to find. I get mine from Johnstone Supply. All they do is HVAC.