I'm finally determined to fix the leak in my Formula. I have bought a sniffer, but it didn't point to a definite leak. I need to try it again, as I made some mistakes using. However, I also want to use UV dye. I've been watching a bunch of youtube videos on AC repair, and (surprise) I'm getting conflicting info. I want to inject dye into my AC system, but I have a few questions first. 1. I know that air in the system is bad, but how much air does it take to cause a problem? Do I need to worry about the small amount of air in the service line when using a can of R134 with dye? 2. If I DO need to worry about it, how do you inject dye into an AC system without also introducing air? 3. Can the dye be cleaned off? If so, with what? One of the problems of using dye is that the low side port will have dye on it. If that's also the source of the leak, then you might miss is, as you will expect dye around that port. Also, it's possible that there's dye in your engine bay, but it's from an earlier leak. I plan on examining my system with a blacklight before doing anything. If I find dye, I'd like to clean it off, then put in more dye, and see where it shows up. 4. What's the best and/or easiest way to get the dye into the system? 5. Will the dye stay in there forever? I.e. if there is dye in there after the leak is fixed, and another leak appears a few years down the road, can I expect to be able to find the leak by looking for the dye?
BTW, right now, my system is empty. I WILL need to replace the accumulator. Do I need to worry about doing that before I get the leak fixed? Say, I get some R134 with dye into my system, enough to get the compressor to cycle... will it matter that the accumulator needs replacing if I only let the compressor run while I'm troubleshooting it?
If your system is empty you just open the dryer and pour in the dye. Being empty you have to vac it down anyway so no worry about air. If it is a big leak use "dry" shop air and then use a spray bottle with soapy water to find the leak. (dry = use a water separator on the line) IE: free, no waste of 134a, BTW wally world has 134a for $4.88 a can, super cheap. Then fix then leak, vac in down for 30 mins and charge it up.
Being your going to replace the accumulator, use the air first, find the leak, then replace it with the dye (and oil)then vac and charge. BTW replace the orifice tube too, cheap under $3
[This message has been edited by sardonyx247 (edited 08-04-2017).]
Re question about introducing air, what you would do is draw a vacuum on the manifold gauge set before opening the valves to charge the system with dye. However if your system is currently "full" you would be adding too much refrigerant just adding more in like that.
The proper way is to evacuate fully, add the dye then recharge fully. Usually though to find a leak my AC tech would evacuate then charge with nitrogen and look for bubbles
Dye testing then you will likely open the system to fix whatever. IOW you don't care about small amount of air to install dye. Dye in it depends how you do it. If pressurize dye and/or sealers then use short fill kit so product goes into the system. Anything kit w/ <= 12" hose is good. Note: "Canned" oil, dye, and many sealers are install w/ can upside down. Follow label direction. (Never install Refrig cans this way!) If dye uses a wrench to push the dye in the system then follow directions for use. Other types but don't have time to type all.
Dye is in there forever unless you have huge leaks, flush, etc. So You often don't need to add more dye to find more leaks.
I believe can clean up dye using alcohol or even soap/water. Many other things can damage rubber/plastic parts like carb and brake cleaners can eat plastic.
Air in the system likely means water too. Air always has moisture. Need a vac pump and a gauge set. You need to vacuum out and leave it pump down to make oil etc to release the water when done fixing your leak. pump down. close manifold valves and turn off. watch system gauge to see vacuum rise and time. water can act like small leaks masking low gauge to rise while oil and drier is letting water go. repeat pumping down etc until gauge stays down for 20-30 minutes. That can be a few to many cycles depending how bad the water problem is.
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If your system is empty you just open the dryer and pour in the dye. Being empty you have to vac it down anyway so no worry about air. If it is a big leak use "dry" shop air and then use a spray bottle with soapy water to find the leak. (dry = use a water separator on the line) IE: free, no waste of 134a, BTW wally world has 134a for $4.88 a can, super cheap. Then fix then leak, vac in down for 30 mins and charge it up.
Being your going to replace the accumulator, use the air first, find the leak, then replace it with the dye (and oil)then vac and charge. BTW replace the orifice tube too, cheap under $3
Good way to have more problems because standard air compressor systems often have water oil and dirt in the hoses and plumbing. Air Oils can be big problems w/ AC oils. Standard air drying/filtering for most shops of any kind get most of crap out but not enough for this use. Most have the drier/filter at the compressor and nothing after. I seen water filled hoses etc at many shops even when they have best driers at the compressor. Cheap driers/filters you get at HF Sears etc are junk for this and often for painting too.
You never want to introduce air in the A/C system. The system has to be evacuated to 29.5 in/hg and must hold that vacuum before recharging. When recharging you can purchase R-134a with an amount of dye in it. After charging you can pin point the leak with a UV lamp. Spots that leak will glow under the light. Whenever an A/C system is opened, the accumulator must be replaced. It contains desiccant and if the system stays charged, it will remove a small amount of water. When exposed to air the accumulator will saturate. You are going to use R-134a to find that leak and then you must drain it out when fixing the leak. There is no other way that I know of to locate the leak. Two areas that are most likely to leak are the connections to the manifold near the firewall, the connections in back of the compressor and the compressor shaft seal that is in back of the pulley/clutch. I would check those areas first. My guess is that if the compressor is original, its the shaft seal.
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Originally posted by sardonyx247:BTW wally world has 134a for $4.88 a can, super cheap.
Yep. Already bought a few cans. Great price.
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Originally posted by sardonyx247:BTW replace the orifice tube too, cheap under $3
Good idea.
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Originally posted by theogre:Need a vac pump and a gauge set.
I have those, and a sniffer, and a black light for detecting uv dye.
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Originally posted by Dennis LaGrua:When exposed to air the accumulator will saturate.
It seems like you should be able to un-saturate the accumulator by vacuuming down the system. That's supposed to remove moisture from the system, right? Why doesn't it remove moisture from the accumulator?
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Originally posted by Dennis LaGrua:My guess is that if the compressor is original, its the shaft seal.
The compressor is original. I hope that's not it. That's the most expensive and most difficult part to replace.
Originally posted by Dennis LaGrua: Whenever an A/C system is opened, the accumulator must be replaced. It contains desiccant and if the system stays charged, it will remove a small amount of water. When exposed to air the accumulator will saturate. You are going to use R-134a to find that leak and then you must drain it out when fixing the leak. There is no other way that I know of to locate the leak. Two areas that are most likely to leak are the connections to the manifold near the firewall, the connections in back of the compressor and the compressor shaft seal that is in back of the pulley/clutch. I would check those areas first. My guess is that if the compressor is original, its the shaft seal.
Replacing acc/drier... New units are not sealed to keep out water for storage in inventory. IOW They have same problem.
The desiccant will boil off the water under vacuum but can take a long time. Same for R134 oils that, like Brake Fluid, loves to hold water. Plus pulled the first vacuum can cool the AC enough to freeze water. Is why I used method above. Running the pump for hours just wears the pump for little results.
You should replace acc/drier when switch from R12 to R134. The old R12 units have desiccant that won't work w/ R134. (New units work w/ both.) Replace 30 plus year old drier is a good plan too even staying w/ R12. the old desiccant bags can break causing problems. All New/rebuild compressor warranty require to have a new acc/drier for this and other reasons.
Two areas that are most likely to leak are the connections to the manifold near the firewall, the connections in back of the compressor and the compressor shaft seal that is in back of the pulley/clutch. I would check those areas first. My guess is that if the compressor is original, its the shaft seal.
On my Indy I found my leak at a connection under the spare tire tub. It's in a line that goes to the condenser in front of the radiator. You can see it from below, but that's all. Pull the tub to change the O-ring.
[QUOTE]Originally posted by Dennis LaGrua: Whenever an A/C system is opened, the accumulator must be replaced. It contains desiccant and if the system stays charged, it will remove a small amount of water. When exposed to air the accumulator will saturate. You are going to use R-134a to find that leak and then you must drain it out when fixing the leak. There is no other way that I know of to locate the leak. Two areas that are most likely to leak are the connections to the manifold near the firewall, the connections in back of the compressor and the compressor shaft seal that is in back of the pulley/clutch. I would check those areas first. My guess is that if the compressor is original, its the shaft seal.
Replacing acc/drier... New units are not sealed to keep out water for storage in inventory. IOW They have same problem.
The desiccant will boil off the water under vacuum but can take a long time. Same for R134 oils that, like Brake Fluid, loves to hold water. Plus pulled the first vacuum can cool the AC enough to freeze water. Is why I used method above. Running the pump for hours just wears the pump for little results.
You should replace acc/drier when switch from R12 to R134. The old R12 units have desiccant that won't work w/ R134. (New units work w/ both.) Replace 30 plus year old drier is a good plan too even staying w/ R12. the old desiccant bags can break causing problems. All New/rebuild compressor warranty require to have a new acc/drier for this and other reasons.[/QUOTE]
Every new unit I've bought has been vacuumed down. I have never bought a new one off the shelf that was pre exposed to air.
Originally posted by wgpierce: Every new unit I've bought has been vacuumed down. I have never bought a new one off the shelf that was pre exposed to air.
I have but haven't got one in years. Either way Desiccant will give up water under a vacuum. often easier then the oils like POE and PAG. (old mineral oil w/ R12 isn't as bad) If POE/PAG system has been open for a day or more then expect oil issues. Is a newer PAG doesn't drink but most system are full of the old type.
I did some double checking... POE used w/ R12 conversion love to drink... And apparently really Really hates to give that water under vacuum. I knew first but not second part. So cars w/ R12 conversions changing acc/drier to remove oil may not be enough for systems w/o some refrigerate pressure to keep water out. Many have these systems open for weeks... Might have all holes taped/plugged very tightly while working but many to most don't then quickly recharge after other work is done... then have problems week to months after w/ dead compressor even black death. Polluted/"wet" oil can cause this.
Poe is How bad for water problems? Tecumseh (Pdf) says do not leave compressor etc open more then 15 minutes on several pages because POE drinks very fast. PDF is for HVAC but you get the problem... (Tecumseh/York compressors where used by Ford and others.)
Replacing the accumulator/dryer... The system was converted to R134 several years ago in the winter. I DID try it as soon as I got home, and the compressor cycled, but since it was cold outside, I didn't leave it running. When I needed it in the Spring, it wouldn't work. That project's been on the back burner since then. So the question is... do I need to replace the accumulator? Before answering that, here's what I've tried:
- Vacuumed system down for 10 minutes. The gauge got to 31" Hg. Not possible, I think, but that's what the gauge showed. - After 30 minutes, the vacuum was almost all gone. Looked like < 5" Hg.
Repeated this 4 more times. The last two times, the vacuum time was 30 minutes. Each time, the vacuum dropped to < 5" Hg after 30 minutes. Would this suggest that: - I need to replace the accumulator? - I should keep trying to vacuum down the system until it holds? - Or do I definitely have a leak? I have always assumed I had a leak.
Which orifice tube is needed? On Rock Auto, I see several. Some are listed as OE replacement. Would that be for R12 or R134?
On another vehicle (a Ford Ranger I just bought as a work truck), I had success with it. It started off empty. Supposedly, it has a leak, so I put a shot of dye in it before getting started. Then vacuumed it down for 30 minutes. Then it held the vacuum for 30 minutes, so I put in the specified amount of R134, and it cools great now. I'll have to see for how long. If it DOES leak out, I'll get to see if the dye works as advertised.
After charging the Ranger, I had a half can of R134 left over. The Ranger took 30 oz, which is 2.5 cans. So I hooked up the low side line to the low port on my Fiero, and the other end to the vacuum pump, vacuumed it for 15 minutes, then put in a shot of dye, and then the half can of R134, which was enough to get the compressor to cycle. My sniffer didn't detect anything at the front, but I DID get a hit at the back side of the compressor (side opposite the pulley). I couldn't get good enough access to see if it was the low side or high side, but it's definitely leaking at the compressor. I let it run for about 10 minutes, then I had to go do something else for about an hour. When I went back out, the compressor wouldn't cycle. I didn't check pressures, but it had leaked enough to prevent the compressor from cycling. I also checked around for dye with a black light. It sprayed a bit when I removed the dye can from the low port, so there was dye all over the place from that. I cleaned that up, and didn't see anything that looked like evidence of an actual leak. I looked around the compressor, too and saw nothing.
So I figure my compressor is bad, or the seals at the fittings on the compressor. Can I get new seals? If so, where? How do I determine if I have a bad compressor?
Don't forget you can also pressure test it. Most A/C guys will use nitrogen - lot of times I will cheat and use Mig mix - it's pretty well inert as well, and I have it handy. Run the pressure up a bit above static pressure to chaeck for leaks on the low pressure side of the system.
Don't forget you can also pressure test it. Most A/C guys will use nitrogen - lot of times I will cheat and use Mig mix - it's pretty well inert as well, and I have it handy. Run the pressure up a bit above static pressure to chaeck for leaks on the low pressure side of the system.
I don't have access to nitrogen, nor do I have any other way to pressurize the system, other than putting in R134.
I just ordered (hopefully) all the o-rings needed to replace them all. I plan to replace every seal in the system. Depending on what I find when I take the orifice tube out, I may flush the system, too. I may flush it anyway. I don't really know what was done to it when I had it converted by a shop from R12 to R134. I don't know if any of the seals were replaced, and I don't know what oil they used. In hindsight, I wish I'd done the job myself.
