Not worry about the O Ring ..But i know they are good source of fail , this is the 1st time for me to work on a AC system, I am learning by asking all questions . Yes there is a gunk caked up around if i recall it the fitting by either the dryer can out put or input the big house that always gets on the way when you try to remove your fuel filter
AC service possibile conversion
- Thread starter Spun4Fun
- Start date
G. Mann
Full Access Member
First put a set of gages on your system and check if you have any charge remaining.. BEFORE you pull a vacuum on the system..
Pulling a vacuum on the system will evacuate all coolant you have in the system.. so IF you have R12 remaining.. you likely still have a sealed system.. just lost some charge over time.
If you pull vacuum.. draw it down and then close off the system and watch how fast it loses vacuum... this will tell you if you have leaks or not.. and how big the leaks are.. It should hold vacuum for 45 minutes to 1 hr. with no drop.
If you have a tight system.. add some refrigerant stop leak, and R12, to get the required hi/lo pressures.
Should be good.
IF you have leaks, fix them, then pull vacuum again to check you got it sealed up.. then if it's good.. add freon 12 and enjoy your cold AC.. Or make the conversion to 134... you call since you open the system anyway to reseal it..
Pulling a vacuum on the system will evacuate all coolant you have in the system.. so IF you have R12 remaining.. you likely still have a sealed system.. just lost some charge over time.
If you pull vacuum.. draw it down and then close off the system and watch how fast it loses vacuum... this will tell you if you have leaks or not.. and how big the leaks are.. It should hold vacuum for 45 minutes to 1 hr. with no drop.
If you have a tight system.. add some refrigerant stop leak, and R12, to get the required hi/lo pressures.
Should be good.
IF you have leaks, fix them, then pull vacuum again to check you got it sealed up.. then if it's good.. add freon 12 and enjoy your cold AC.. Or make the conversion to 134... you call since you open the system anyway to reseal it..
Here is one, a leak detector.http://www.harborfreight.com/catalogsearch/result?q=refrigerant+leak+detector
It's a new one on me, but since when do you pull a vacuum to find a refrigerant leak?
I've got an old fashion leak detector, a special nozzle on a propane bottle with a hose attached, the flame will turn green if it sucks up any refrig., you have to charge the system just enough that the AC clutch kicks in, run the AC on MAX and Hi fan, then probe around with the hose, you can even use a small propane torch if your careful without the special nozzle, the flame will turn green at a leak, just don't aim the flame at any fitting, just close to it.
You pull a vacuum to evacuate a system if it's been opened, vacuum should be pulled for at least 2 hrs., any leak should be repaired first.
Google, changing refrigerant in a automotive AC
It's a new one on me, but since when do you pull a vacuum to find a refrigerant leak?
I've got an old fashion leak detector, a special nozzle on a propane bottle with a hose attached, the flame will turn green if it sucks up any refrig., you have to charge the system just enough that the AC clutch kicks in, run the AC on MAX and Hi fan, then probe around with the hose, you can even use a small propane torch if your careful without the special nozzle, the flame will turn green at a leak, just don't aim the flame at any fitting, just close to it.
You pull a vacuum to evacuate a system if it's been opened, vacuum should be pulled for at least 2 hrs., any leak should be repaired first.
Google, changing refrigerant in a automotive AC
icanfixall
Official GMM hand model
So as its been said. Don't pull a vacuum on a system that has ANY charge left in it. I'm sorry I should have mentioned this before. As I compose what I post I think and see what has to be done. All that does not always get posted. Some kind of a mental disconnect I guess. Pulling vacuum on an mt closed system can be easy or hard. It depends on the size of the leak if you have one. the times posted for determining the leak if any exists is close enough. Now you can also do this but only if the system has no freon in it. Apply about 50 to 10 lbs of PRESSURE to the system. Now squirt some soapy water on all the hose connections and into the front of the compressor seal area. Any foam tells you there is a leak there. Repair the leak ans pull a vacuum to check. If it holds then add freon. Do your eyes a favor. Buy a face mast to protect your eyes from exploding freon from a bad hose or seal. Freon in the eyes will hurt you bad. We can't afford to loose an eye nor a finger so be careful.
G. Mann
Full Access Member
Dye check and black light works for me.. for hard to find leaks especially.. A can of dye check into the system and enough refrigerant to get it to work for a while to push some dye out the leak.
The pull a vacuum on a newly assembled system procedure is one I've used for 30 years... If it won't hold a vacuum then don't lose the money cost of the refrigerant [at R12 prices these days] Before, when R12 was cheap, it just saved a load of rework by pulling vacuum before you charged the system, if you had a leak.
The pull a vacuum on a newly assembled system procedure is one I've used for 30 years... If it won't hold a vacuum then don't lose the money cost of the refrigerant [at R12 prices these days] Before, when R12 was cheap, it just saved a load of rework by pulling vacuum before you charged the system, if you had a leak.
ToughOldFord
The Cold Glow-Plug
Bad advice there. That stuff plugs up everything. I had to buy a $500 filter to keep stop leak out of my AC charging stations.
You got that right Chris, when the price of R12 went sky hi before the 134a era, people were even putting propane and God knows what else in AC systems, all that **** can sure ruin a Vac system at a legit AC service. You know how that works, people want to sell a vehicle with the AC working so they charge it with anything, pretty soon it quits working and the buyer takes it to a legit service, whoa and behold, buyer has a $500 service cost.
If there is no charge left in the system, change out the o-rings, drier,clean the evaporator and condenser with a flush, pull a vacuum and let it sit. I usually throw a charge of Nitrogen into the system and let it sit a while to verify that there are no leaks. If there are none, I'd say pull the vacuum again and have it filled with R12 as it's more efficient and your hoses and system is sized for that refrigerant. If you want to convert to 134A, you'll need to change out a bit more than the O rings to retrofit. As long as these systems hold their charge, it's worth trying to stick with the original R12. But if you really want to think long term or have doubts, or want to do it all yourself, may as well change over.
No need to change anything when changing to r134a. I have done it many times, the system will work fine by pulling a vacuum on it, fix any leaks, and put the r134a with the ester oil in it. No flushing needed, no special o-rings , no special orifice, no special hoses.
That's what I've always done.
When 134a was first deemed by EPA, there was a lot of discusion about the hoses, claimed the 134a had smaller molecules and the hoses would leak all the refrig out. BS Some refrig services made big bucks changing everything.
Well, thinking back on it, I have always changed the accumulator by default, the leak was usually the compressor and I change the accumulator when the compressor is changed. So I can't comment on the above statement.
The only explanation I have heard about the o-rings and hoses is the r12 "seasons" the o-rings and hoses after awhile, and afterward they seem resistant to the r134a leaking through. I think most replacement hoses now are r134a compatible but I would have to wonder if you found a old NOS set of hoses on ebay or somewhere that have never been used, would they actually work with 134a or would they leak.
You would be amazed at the amount of people that don't change a dryer,add oil etc.they think that they can just squirt refrigerant in and it will work. Don't know what an orifice or expansion valve is etc.
My favorite was a jaguar owner " I put 6 cans in it and its still not cold ".
My favorite was a jaguar owner " I put 6 cans in it and its still not cold ".
