HOLY $HIT....I HAVE COLD A/C!!!!-LONG post
03-25-2007, 08:01 PM
#1
Le Mans Master
Thread Starter
HOLY $HIT....I HAVE COLD A/C!!!!-LONG post
So today I decide to play around while cruising the vette and I stick a thermometer in the center vents for testing. Cruising with everything turned off and the hot/cold control on cold, I have about 95-100*s on average coming through...Turning the AC on max with the blower on high gets the temp to about 85-88*. No doubt its just the blower circulating it and its dropping the temp some.
So I go to a buddy's house that does AC work and tell him what its doing, he suggests dumping some test refrigerant in there thats like R12. Its only for testing but its like an R12 blend with something else. He only had 3 cans so we dumped em in. The system requires 4 cans. Anyway after about 20 mins, the temps start dropping in the car like crazy at idle. I am freaking out, its actually cold air coming in. We idle the car about 20 mins or so and the temp gets to about 48-50*. The lines are sweating and nothing is freezing up so it all seems to be working. WE go for a cruise for about 30 mins on a 50mph road the temp drops to 45*. I drop my buddy off, go to my house to get another thermometer because I can't believe this $hit. I drive the car for about an hour, mostly at speed but with some idling here and there, the temps averaged 41-42* on one thermometer and 43-45* on the other. I stopped got gas, started it up and it cooled right back down again. Now after about an hour and 15 mins, I pull up in the driveway and the first thermometer is 39-40* and the other is 40-41*. I actually had to turn the blower down to the med speed it got so cool in the car. The insulation really seems to help, thats for sure.
NOW the problem is, WILL IT HOLD IT? LOL this thing has not had freon in it for 20 yrs so I am sure its got a leak. My friend wants me to drive it for a week and measure the temps. If it starts getting noticeably warmer, we will sniff it for leaks...IF it stays cool, he wants to pull a vacuum on it and dump another can in there to top it off. This is not even real R12 freon but it works and is only like $5 a can. Even if it leaks it all out, it still proves to me
A) Everything in my system works(poa valve, expansion valve, evaporator, condensor etc)
B) The AC will definetly overcome what hot air I have entering the system through the firewall, AC system etc. Now I don't have to chase my tail around looking for hot air leaks I'm sure I will never get completely fixed.
Keep in mind its only 78-80* outside right now and I know when its 95-100* with tons of humidity, it probably won't blow but 50-60* but hey, its working.
I am completely stoked about this thing working. The clock is ticking to see if it holds.
Sorry for the long post but I just wanted to give all the details.
So I go to a buddy's house that does AC work and tell him what its doing, he suggests dumping some test refrigerant in there thats like R12. Its only for testing but its like an R12 blend with something else. He only had 3 cans so we dumped em in. The system requires 4 cans. Anyway after about 20 mins, the temps start dropping in the car like crazy at idle. I am freaking out, its actually cold air coming in. We idle the car about 20 mins or so and the temp gets to about 48-50*. The lines are sweating and nothing is freezing up so it all seems to be working. WE go for a cruise for about 30 mins on a 50mph road the temp drops to 45*. I drop my buddy off, go to my house to get another thermometer because I can't believe this $hit. I drive the car for about an hour, mostly at speed but with some idling here and there, the temps averaged 41-42* on one thermometer and 43-45* on the other. I stopped got gas, started it up and it cooled right back down again. Now after about an hour and 15 mins, I pull up in the driveway and the first thermometer is 39-40* and the other is 40-41*. I actually had to turn the blower down to the med speed it got so cool in the car. The insulation really seems to help, thats for sure.
NOW the problem is, WILL IT HOLD IT? LOL this thing has not had freon in it for 20 yrs so I am sure its got a leak. My friend wants me to drive it for a week and measure the temps. If it starts getting noticeably warmer, we will sniff it for leaks...IF it stays cool, he wants to pull a vacuum on it and dump another can in there to top it off. This is not even real R12 freon but it works and is only like $5 a can. Even if it leaks it all out, it still proves to me
A) Everything in my system works(poa valve, expansion valve, evaporator, condensor etc)
B) The AC will definetly overcome what hot air I have entering the system through the firewall, AC system etc. Now I don't have to chase my tail around looking for hot air leaks I'm sure I will never get completely fixed.
Keep in mind its only 78-80* outside right now and I know when its 95-100* with tons of humidity, it probably won't blow but 50-60* but hey, its working.
I am completely stoked about this thing working. The clock is ticking to see if it holds.
Sorry for the long post but I just wanted to give all the details.
03-25-2007, 08:08 PM
#2
Melting Slicks
So - you have to turn it down too ! That is wierd even though itg has not had freon in it for so long...... Hope it has no problems - keep us posted.... I can't wait to say the same about mine !
03-26-2007, 09:13 AM
#9
Le Mans Master
Thread Starter
OK I talked to the guy that filled it up. He put in "Freon 12", also known as "Freeze 12" which is an R12 replacement. Its actually a blend of R12 freon and some other stuff. He says its good to use on old systems for testing and is even safe to use long term ASSUMING there is no leaks. He told me that slow leaks are the worst because the blended freon breaks down and seperates, then certain ingredients escape the system and others stay in. The ingredients that stay in the system can be acidic and actually hurt or destroy the AC system componets.
He told me to drive it and watch the discharge air temps, if they stay consistant within range and the system cools for extended periods, to let it ride and see what happens. If the AC starts blowing warmer air, that means its gotta leak and at that time, we need to pull a vacuum on it and get all the Freon 12 out, find the leak and refill with regular freon after the leaks are fixed. He also told me that slow freon leaks are HARD to find, especially if its in the evaporator.
For now I am gonna let it ride and see what happens. The AC guy could not believe that this system didn't cycle on and off and had no low pressure switch. He also couldn't believe that my evaporator did not freeze up with the compressor running the whole time.
This is good info. I have never known $hit about AC but I am studying up now.
He told me to drive it and watch the discharge air temps, if they stay consistant within range and the system cools for extended periods, to let it ride and see what happens. If the AC starts blowing warmer air, that means its gotta leak and at that time, we need to pull a vacuum on it and get all the Freon 12 out, find the leak and refill with regular freon after the leaks are fixed. He also told me that slow freon leaks are HARD to find, especially if its in the evaporator.
For now I am gonna let it ride and see what happens. The AC guy could not believe that this system didn't cycle on and off and had no low pressure switch. He also couldn't believe that my evaporator did not freeze up with the compressor running the whole time.
This is good info. I have never known $hit about AC but I am studying up now.
03-26-2007, 09:36 AM
#10
Le Mans Master
Thread Starter
Just another test note, I just stuck the thermometer in my truck which was the colder reading of the two I had in the vette, my truck is a 05 F150 with the 4.6 v8. With it on Max AC, full cold its blowing 39-40* with an outside temp of 70* so the vette is right in line with my truck on this thermometer. Not sure which thermometer is more acurate, there is about a 2-3 degree difference in them every time I use them but either way, its BOTTOM 40s. Ofcourse the 2nd speed of the fan in the truck is equivalent to HI in the vette...LOL
Now I gotta find out about the C4 blower mod.
Now I gotta find out about the C4 blower mod.
03-26-2007, 10:33 AM
#11
Race Director
OK I talked to the guy that filled it up. He put in "Freon 12", also known as "Freeze 12" which is an R12 replacement. Its actually a blend of R12 freon and some other stuff. He says its good to use on old systems for testing and is even safe to use long term ASSUMING there is no leaks. He told me that slow leaks are the worst because the blended freon breaks down and seperates, then certain ingredients escape the system and others stay in. The ingredients that stay in the system can be acidic and actually hurt or destroy the AC system componets.
He told me to drive it and watch the discharge air temps, if they stay consistant within range and the system cools for extended periods, to let it ride and see what happens. If the AC starts blowing warmer air, that means its gotta leak and at that time, we need to pull a vacuum on it and get all the Freon 12 out, find the leak and refill with regular freon after the leaks are fixed. He also told me that slow freon leaks are HARD to find, especially if its in the evaporator.
For now I am gonna let it ride and see what happens. The AC guy could not believe that this system didn't cycle on and off and had no low pressure switch. He also couldn't believe that my evaporator did not freeze up with the compressor running the whole time.
This is good info. I have never known $hit about AC but I am studying up now.
He told me to drive it and watch the discharge air temps, if they stay consistant within range and the system cools for extended periods, to let it ride and see what happens. If the AC starts blowing warmer air, that means its gotta leak and at that time, we need to pull a vacuum on it and get all the Freon 12 out, find the leak and refill with regular freon after the leaks are fixed. He also told me that slow freon leaks are HARD to find, especially if its in the evaporator.
For now I am gonna let it ride and see what happens. The AC guy could not believe that this system didn't cycle on and off and had no low pressure switch. He also couldn't believe that my evaporator did not freeze up with the compressor running the whole time.
This is good info. I have never known $hit about AC but I am studying up now.
03-26-2007, 10:50 AM
#12
Le Mans Master
Thread Starter
I tried to tell him these don't clutch in and out but he didn't believe me.. Then he said that SOMETHING has got to keep the pressure down so it won't freeze the evap core. We checked the head pressure, at idle it was 140psi and at 2000 rpms it was like 240lbs. He said that was pretty good.
I told him I don't know what regulates the system and keeps it from freezing up but I know it doesn't clutch in and out which I like.
I just hope that blending Freon 12 doesn't F up my compressor.
Anyone know how to check or add "oil" to the compressor?
03-26-2007, 12:16 PM
#13
Race Director
I tried to tell him these don't clutch in and out but he didn't believe me.. Then he said that SOMETHING has got to keep the pressure down so it won't freeze the evap core. We checked the head pressure, at idle it was 140psi and at 2000 rpms it was like 240lbs. He said that was pretty good.
I told him I don't know what regulates the system and keeps it from freezing up but I know it doesn't clutch in and out which I like.
I just hope that blending Freon 12 doesn't F up my compressor.
Anyone know how to check or add "oil" to the compressor?
I told him I don't know what regulates the system and keeps it from freezing up but I know it doesn't clutch in and out which I like.
I just hope that blending Freon 12 doesn't F up my compressor.
Anyone know how to check or add "oil" to the compressor?
Just needs a primer on the old systems.
Your really better to convert to 134a or stay with r12 on the oiling issue.
You have to evacuate the refrigerant and flush etc to refill with the correct amount of oil for the system.
03-26-2007, 01:59 PM
#14
Le Mans Master
Thread Starter
I am not really interested in converting to R134. If mine does leak, I will just sniff it out, find it, fix it and refill with the Freeze 12 for testing, then maybe evacuate it and reinstall the R12 after we know there is no leaks. OR I might just leave the Freeze 12.
I am gonna wait and see what it does for now, I just don't want to burn the compressor up if its supposed to have oil in it and it doesn't.
03-26-2007, 02:34 PM
#15
Race Director
If you have the old a6 compressor it does have an oil sump and a certain amount of oil will stay there.
A/c systems keep the oil in suspension so you must evacuate the system, flush it and refill with the proper amount. No way of checking it. Even the compressors with a dipstick is just a bunch of hype.
The Freeze 12, as your friend mentioned, is only a small % compatable with the mineral oil etc, so it can be a crap shoot even at best. Your dice, your parts, your money.
Accepted method for leak testing is with nitrogen and dye, cheapest way.
A/c systems keep the oil in suspension so you must evacuate the system, flush it and refill with the proper amount. No way of checking it. Even the compressors with a dipstick is just a bunch of hype.
The Freeze 12, as your friend mentioned, is only a small % compatable with the mineral oil etc, so it can be a crap shoot even at best. Your dice, your parts, your money.
Accepted method for leak testing is with nitrogen and dye, cheapest way.
03-26-2007, 03:46 PM
#16
Regulating the Temp!
The old systems have an expansion valve that regulates the constant flow of freon to the evaporator.
There is a thermobulb that comes off the expansion valve and is attached to the outlet of the evaporator. It is usually hidden under a tar like insulating material. This senses the outlet temp and regulates the freon (via the expansion valve) into the evaporator.
This regulation maintains the evaporator at a temperature just above freezing. (38-40 degreese).
Bob
There is a thermobulb that comes off the expansion valve and is attached to the outlet of the evaporator. It is usually hidden under a tar like insulating material. This senses the outlet temp and regulates the freon (via the expansion valve) into the evaporator.
This regulation maintains the evaporator at a temperature just above freezing. (38-40 degreese).
Bob
03-26-2007, 04:15 PM
#17
Le Mans Master
Thread Starter
The old systems have an expansion valve that regulates the constant flow of freon to the evaporator.
There is a thermobulb that comes off the expansion valve and is attached to the outlet of the evaporator. It is usually hidden under a tar like insulating material. This senses the outlet temp and regulates the freon (via the expansion valve) into the evaporator.
This regulation maintains the evaporator at a temperature just above freezing. (38-40 degreese).
Bob
There is a thermobulb that comes off the expansion valve and is attached to the outlet of the evaporator. It is usually hidden under a tar like insulating material. This senses the outlet temp and regulates the freon (via the expansion valve) into the evaporator.
This regulation maintains the evaporator at a temperature just above freezing. (38-40 degreese).
Bob
Noonie, I guess if mine leaks out, I will try the dye method to find the leak. Hopefully it doesn't waste my compressor. Like you said, its a gamble. Hell if it works a couple years and I don't have to spend any $$ on it, I can't complain when it does crap out.
I just ordered new T-Top seals and window seals so I can seal this baby up tight to keep er cool during the sweltering summers here..
Next mod, C4 blower.
03-27-2007, 11:34 AM
#19
Melting Slicks
If you have the old a6 compressor it does have an oil sump and a certain amount of oil will stay there.
A/c systems keep the oil in suspension so you must evacuate the system, flush it and refill with the proper amount. No way of checking it. Even the compressors with a dipstick is just a bunch of hype.
The Freeze 12, as your friend mentioned, is only a small % compatable with the mineral oil etc, so it can be a crap shoot even at best. Your dice, your parts, your money.
Accepted method for leak testing is with nitrogen and dye, cheapest way.
A/c systems keep the oil in suspension so you must evacuate the system, flush it and refill with the proper amount. No way of checking it. Even the compressors with a dipstick is just a bunch of hype.
The Freeze 12, as your friend mentioned, is only a small % compatable with the mineral oil etc, so it can be a crap shoot even at best. Your dice, your parts, your money.
Accepted method for leak testing is with nitrogen and dye, cheapest way.
I'd read that when a system is evacuated, no oil is removed. True?
Jim
03-27-2007, 11:45 AM
#20
Burning Brakes
My 82 blows cold. I was told it was converted over to accept the new refridgerant. I am not sure what the new refridgerant is though. You guys Have any Idea what it could be? However the engine runs like crap when the AC is on. I favor the windows down and tops out anyway!