A/C Help did read archieves
05-26-2018, 09:59 AM
#1
Burning Brakes
Thread Starter
A/C Help did read archieves
Tried to charge the A/C following the 101 thread. Not sure how it went but must have gotten some R-12 in it but no cold air out. I noticed the compressor did not kick in-clutch needed to be freed up which I did. Here's the question - the green wire has power and when I looked at the Dr.Rebuild wiring diagram it also shows a ground at the compressor. Should there be one there? I don't remember ever seeing one but the for that matter the A/C never worked. thanks for the help.
Joe
65 327/350 factory air coupe
Joe
65 327/350 factory air coupe
05-26-2018, 10:33 AM
#2
Safety Car
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Tried to charge the A/C following the 101 thread. Not sure how it went but must have gotten some R-12 in it but no cold air out. I noticed the compressor did not kick in-clutch needed to be freed up which I did. Here's the question - the green wire has power and when I looked at the Dr.Rebuild wiring diagram it also shows a ground at the compressor. Should there be one there? I don't remember ever seeing one but the for that matter the A/C never worked. thanks for the help.
Joe
65 327/350 factory air coupe
Joe
65 327/350 factory air coupe
For us to help you we would at the least need to know the high side and low side pressures and ambient temperature you have.
Dan
05-26-2018, 10:43 AM
#3
Race Director
A6 compressor clutch has a 16 gage green 12 volt power wire and a 14 gage black ground wire to complete the circuit. Both wires are part of the single AC compressor wiring clip. Other end of ground wire goes to compressor bracket on engine. I will look later today or tomorrow and tell you exactly where it connects............but my car is in the garage under a cover at this moment. Maybe someone else can help between now and then. 
After evacuating system and verifying that there are no air leaks, take extra precaution when unhooking vacuum pump and hooking up R12 supply to make sure NO air get trapped in the refrigeration gage set lines or gage manifold. A lot of folks do not do this step correctly and wind up getting air into the system during the initial charge. Let me know if you need details on this.
FWIW.
Larry
After evacuating system and verifying that there are no air leaks, take extra precaution when unhooking vacuum pump and hooking up R12 supply to make sure NO air get trapped in the refrigeration gage set lines or gage manifold. A lot of folks do not do this step correctly and wind up getting air into the system during the initial charge. Let me know if you need details on this.
FWIW.
Larry
Last edited by Powershift; 05-26-2018 at 10:45 AM.
05-26-2018, 11:13 AM
#4
Melting Slicks
Clutch ground wire
The clutch coil ground wire is terminated with a ring lug and is installed under the lower/outboard compressor front mounting bolt.
BTW: you said the clutch had to be "freed up". Do you mean it was frozen in the engaged position? You should verify proper clutch engagement with power applied/removed, and the clearance air gap before going further. Many guys use a standard business card as the feeler gage for the gap.
BTW: you said the clutch had to be "freed up". Do you mean it was frozen in the engaged position? You should verify proper clutch engagement with power applied/removed, and the clearance air gap before going further. Many guys use a standard business card as the feeler gage for the gap.
05-26-2018, 12:30 PM
#5
Burning Brakes
Thread Starter
The clutch coil ground wire is terminated with a ring lug and is installed under the lower/outboard compressor front mounting bolt.
BTW: you said the clutch had to be "freed up". Do you mean it was frozen in the engaged position? You should verify proper clutch engagement with power applied/removed, and the clearance air gap before going further. Many guys use a standard business card as the feeler gage for the gap.
BTW: you said the clutch had to be "freed up". Do you mean it was frozen in the engaged position? You should verify proper clutch engagement with power applied/removed, and the clearance air gap before going further. Many guys use a standard business card as the feeler gage for the gap.
I wil put the gauge set back on today for a reading and report back. I assume I can get a reading without the compressor running.
Larry
Thank you for the info on the wire. Please don't go to any extra trouble for me. CC sells the wire for $12 which I should have looked at first. there is a good chance that I did get air in the system since in hooking and unhooking at one point I missed a step for sure.
Mike
It felt like there was a high spot. It freed easily with almost no effort when I put channel locks to it and turns freely by hand.
I'll hook up a temp ground, install the gauges and report back. Thank you all for your quick replies.
Joe
05-26-2018, 02:43 PM
#6
Burning Brakes
Thread Starter
Ran a ground and now have the compressor running. I have no pressure either with or without the compressor on. So where did 3 12oz. cans of
R-12 go? When evacuated the system it held solid and I let it go for about 24 hours.. I could only get 20 lbs of vacuum but I think that is more a faction of the pump I have.
So from here do I try again a fill it with the R-12 or do I go with one of the substitutes? Thanks again for all the help.
Joe
R-12 go? When evacuated the system it held solid and I let it go for about 24 hours.. I could only get 20 lbs of vacuum but I think that is more a faction of the pump I have.
So from here do I try again a fill it with the R-12 or do I go with one of the substitutes? Thanks again for all the help.
Joe
05-26-2018, 03:00 PM
#7
Safety Car
Not to be demeaning at all, but you need onsite help. Anyone around you do ac work? What you are doing is both dangerous to you and your system. If you can’t get a vacuum (not in pounds either) you are at a stop till something gets repaired. Pressure check afterward with something less expensive than R-12.
Last edited by pop23235; 05-26-2018 at 03:03 PM.
05-26-2018, 03:45 PM
#8
Burning Brakes
Thread Starter
[QUOTE=pop23235;1597279585]Not to be demeaning at all, but you need onsite help. Anyone around you do ac work? What you are doing is both dangerous to you and your system. If you can’t get a vacuum (not in pounds either) you are at a stop till something gets repaired. Pressure check afterward with something less expensive than R-12.[/QU
No offense taken I am aware of my short coming in this area but would like to learn. As far as a/c shops around here in northern bergen county, they are none existent.
What I do glean from you is that what I thought was vacuum was not and I am correct in that?
Joe
No offense taken I am aware of my short coming in this area but would like to learn. As far as a/c shops around here in northern bergen county, they are none existent.
What I do glean from you is that what I thought was vacuum was not and I am correct in that?
Joe
05-26-2018, 05:08 PM
#9
Race Director
Joe:
Vacuum is typically measured in inches of mercury (in. HG.). You need a vacuum pump that will pump down to 29.9 in HG or below (i.e.. 29.92 to 29.95). This is the only way to effectively remove both air and moisture in the system. A good vacuum pump will essentially pull the manifold gage needles to the stop/rest point. And a tight and dry system will essentially hold that vacuum overnight without the pump running.
Your compressor seal may now be leaking due to the issues you had with the A6 compressor clutch.
Did you replace the system drier?? If not, you should do this before final charging with R12..
Generally when I have everything buttoned up, I put nitrogen gas or some R22 or R134a refrigerant into the system for a preliminary pressure check. I pressure to about 50 psig. Then I used a soap or SNOOP solution and check every o-ring and joint and rubber hose I have for any leaks. Hoses can be porus or have a small cut thru the hose itself. I also watch the manifold pressure gage to see if it maintains pressure or the pressure goes down. I also use an electronic refrigerant leak detector to test the evaporator core, the condenser core, and the A6 compressor front seal. You cannot use soap/SNOOP on these.
I repair all the leaks.......and pressure test again until no loss of pressure and no soap bubbles.
If (or when) everything is leak free, I then pull a deep vacuum with a vacuum pump and let things stand overnight to check for any small vacuum leaks..........and also to remove any moisture.
If all is okay, I break the vacuum with air, replace the drier with a new one for R12/R134a service, add my system oil, and then pull another deep vacuum for an hour or so. Since the only connections I worked on are the two at the drier, I use new o-rings lubricated with refrigerant oil and hope they seal up. This final vacuum test should confirm this.
At that point I again run the vacuum pump to pump the system down again for any remaining air or moisture and then break vacuum with R12 (or R134a) refrigerant after making absolute sure I have purged any and all air from the lines when disconnecting the vacuum pump and connecting the refrigerant. Remember that you need to even consider the gage manifold itself as a reservoir for a small amount of air............so I blow a bit of refrigerant into the manifold with the red and blue valves still closed to help purge out any chance of air. I do this a few times, blowing thru the refrigerant yellow line with refrigerant to to remove the air.
I then add about 1 can or 1 pound of refrigerant. Change cans and purge lines again if using small cans. Then I start the car, activvate AC and run RPM up to 1500, and slowly add remaining refrigerant. I use both weight of refrigerant added as well as look for absence of bubbles in the drier sight glass.
I also monitor hi and low AC pressures as well as temperature coming from the AC vents in the car cabin.
I can talk you through any and all of these steps if you want. PM for my phone number.
To do the job correctly, you need a Chevrolet Service Manual, good vacuum pump, refrigerant, proper oil, manifold gage set that is reliable, small thermometer for AC vents, a helper/friend to assist, and borrow or buy a refrigerant electronic leak detector for troubleshooting. Also some SNOOP leak check solution. Also new o-rings for any time you break a connection or suspect a o-ring leak.
Hope this helps.
Larry
Vacuum is typically measured in inches of mercury (in. HG.). You need a vacuum pump that will pump down to 29.9 in HG or below (i.e.. 29.92 to 29.95). This is the only way to effectively remove both air and moisture in the system. A good vacuum pump will essentially pull the manifold gage needles to the stop/rest point. And a tight and dry system will essentially hold that vacuum overnight without the pump running.
Your compressor seal may now be leaking due to the issues you had with the A6 compressor clutch.
Did you replace the system drier?? If not, you should do this before final charging with R12..
Generally when I have everything buttoned up, I put nitrogen gas or some R22 or R134a refrigerant into the system for a preliminary pressure check. I pressure to about 50 psig. Then I used a soap or SNOOP solution and check every o-ring and joint and rubber hose I have for any leaks. Hoses can be porus or have a small cut thru the hose itself. I also watch the manifold pressure gage to see if it maintains pressure or the pressure goes down. I also use an electronic refrigerant leak detector to test the evaporator core, the condenser core, and the A6 compressor front seal. You cannot use soap/SNOOP on these.
I repair all the leaks.......and pressure test again until no loss of pressure and no soap bubbles.
If (or when) everything is leak free, I then pull a deep vacuum with a vacuum pump and let things stand overnight to check for any small vacuum leaks..........and also to remove any moisture.
If all is okay, I break the vacuum with air, replace the drier with a new one for R12/R134a service, add my system oil, and then pull another deep vacuum for an hour or so. Since the only connections I worked on are the two at the drier, I use new o-rings lubricated with refrigerant oil and hope they seal up. This final vacuum test should confirm this.
At that point I again run the vacuum pump to pump the system down again for any remaining air or moisture and then break vacuum with R12 (or R134a) refrigerant after making absolute sure I have purged any and all air from the lines when disconnecting the vacuum pump and connecting the refrigerant. Remember that you need to even consider the gage manifold itself as a reservoir for a small amount of air............so I blow a bit of refrigerant into the manifold with the red and blue valves still closed to help purge out any chance of air. I do this a few times, blowing thru the refrigerant yellow line with refrigerant to to remove the air.
I then add about 1 can or 1 pound of refrigerant. Change cans and purge lines again if using small cans. Then I start the car, activvate AC and run RPM up to 1500, and slowly add remaining refrigerant. I use both weight of refrigerant added as well as look for absence of bubbles in the drier sight glass.
I also monitor hi and low AC pressures as well as temperature coming from the AC vents in the car cabin.
I can talk you through any and all of these steps if you want. PM for my phone number.
To do the job correctly, you need a Chevrolet Service Manual, good vacuum pump, refrigerant, proper oil, manifold gage set that is reliable, small thermometer for AC vents, a helper/friend to assist, and borrow or buy a refrigerant electronic leak detector for troubleshooting. Also some SNOOP leak check solution. Also new o-rings for any time you break a connection or suspect a o-ring leak.
Hope this helps.
Larry
Last edited by Powershift; 05-26-2018 at 05:14 PM.
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ah53 (05-26-2018)
05-26-2018, 08:39 PM
#10
Safety Car
I'd sure trust Larry! Might differ a bit, but not significantly. I don't replace the desiccant unless there has been a major system component failure. I never break the vacuum with air. I'd give him a call if I were you.
05-26-2018, 09:54 PM
#12
Safety Car
Member Since: Feb 2012
Posts: 4,532
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05-26-2018, 10:20 PM
#13
Race Director
OP said in opening paragraph that his AC system has been dead for years.....maybe even decades...........drier replacement is good insurance after all this time.
I agree that if you have cylinder dry nitrogen, use it to break vacuum as well as for all pressure tests.. But most folks simply don't have this available to them. My recommendation was to replace drier and re-vacuum system in a short period of time. Moisture intrusion should be low and re-vacuum will pull it back out. Drier is good for I believe 1-2 tablespoons of water removal. But unless OP is doing this in the rain, I do not feel it will harm him or his system for this brief period. But if he can find dry nitrogen, that is what he should use.
Pop and Dan:
I do appreciate your comments..........as I continue to learn as well.
Larry
Last edited by Powershift; 05-26-2018 at 10:22 PM.
05-26-2018, 10:24 PM
#14
Race Director
05-27-2018, 12:03 PM
#15
Race Director
Joe:
Vacuum is typically measured in inches of mercury (in. HG.). You need a vacuum pump that will pump down to 29.9 in HG or below (i.e.. 29.92 to 29.95). This is the only way to effectively remove both air and moisture in the system. A good vacuum pump will essentially pull the manifold gage needles to the stop/rest point. And a tight and dry system will essentially hold that vacuum overnight without the pump running.
Your compressor seal may now be leaking due to the issues you had with the A6 compressor clutch.
Did you replace the system drier?? If not, you should do this before final charging with R12..
Generally when I have everything buttoned up, I put nitrogen gas or some R22 or R134a refrigerant into the system for a preliminary pressure check. I pressure to about 50 psig. Then I used a soap or SNOOP solution and check every o-ring and joint and rubber hose I have for any leaks. Hoses can be porus or have a small cut thru the hose itself. I also watch the manifold pressure gage to see if it maintains pressure or the pressure goes down. I also use an electronic refrigerant leak detector to test the evaporator core, the condenser core, and the A6 compressor front seal. You cannot use soap/SNOOP on these.
I repair all the leaks.......and pressure test again until no loss of pressure and no soap bubbles.
If (or when) everything is leak free, I then pull a deep vacuum with a vacuum pump and let things stand overnight to check for any small vacuum leaks..........and also to remove any moisture.
If all is okay, I break the vacuum with air, replace the drier with a new one for R12/R134a service, add my system oil, and then pull another deep vacuum for an hour or so. Since the only connections I worked on are the two at the drier, I use new o-rings lubricated with refrigerant oil and hope they seal up. This final vacuum test should confirm this.
At that point I again run the vacuum pump to pump the system down again for any remaining air or moisture and then break vacuum with R12 (or R134a) refrigerant after making absolute sure I have purged any and all air from the lines when disconnecting the vacuum pump and connecting the refrigerant. Remember that you need to even consider the gage manifold itself as a reservoir for a small amount of air............so I blow a bit of refrigerant into the manifold with the red and blue valves still closed to help purge out any chance of air. I do this a few times, blowing thru the refrigerant yellow line with refrigerant to to remove the air.
I then add about 1 can or 1 pound of refrigerant. Change cans and purge lines again if using small cans. Then I start the car, activvate AC and run RPM up to 1500, and slowly add remaining refrigerant. I use both weight of refrigerant added as well as look for absence of bubbles in the drier sight glass.
I also monitor hi and low AC pressures as well as temperature coming from the AC vents in the car cabin.
I can talk you through any and all of these steps if you want. PM for my phone number.
To do the job correctly, you need a Chevrolet Service Manual, good vacuum pump, refrigerant, proper oil, manifold gage set that is reliable, small thermometer for AC vents, a helper/friend to assist, and borrow or buy a refrigerant electronic leak detector for troubleshooting. Also some SNOOP leak check solution. Also new o-rings for any time you break a connection or suspect a o-ring leak.
Hope this helps.
Larry
Vacuum is typically measured in inches of mercury (in. HG.). You need a vacuum pump that will pump down to 29.9 in HG or below (i.e.. 29.92 to 29.95). This is the only way to effectively remove both air and moisture in the system. A good vacuum pump will essentially pull the manifold gage needles to the stop/rest point. And a tight and dry system will essentially hold that vacuum overnight without the pump running.
Your compressor seal may now be leaking due to the issues you had with the A6 compressor clutch.
Did you replace the system drier?? If not, you should do this before final charging with R12..
Generally when I have everything buttoned up, I put nitrogen gas or some R22 or R134a refrigerant into the system for a preliminary pressure check. I pressure to about 50 psig. Then I used a soap or SNOOP solution and check every o-ring and joint and rubber hose I have for any leaks. Hoses can be porus or have a small cut thru the hose itself. I also watch the manifold pressure gage to see if it maintains pressure or the pressure goes down. I also use an electronic refrigerant leak detector to test the evaporator core, the condenser core, and the A6 compressor front seal. You cannot use soap/SNOOP on these.
I repair all the leaks.......and pressure test again until no loss of pressure and no soap bubbles.
If (or when) everything is leak free, I then pull a deep vacuum with a vacuum pump and let things stand overnight to check for any small vacuum leaks..........and also to remove any moisture.
If all is okay, I break the vacuum with air, replace the drier with a new one for R12/R134a service, add my system oil, and then pull another deep vacuum for an hour or so. Since the only connections I worked on are the two at the drier, I use new o-rings lubricated with refrigerant oil and hope they seal up. This final vacuum test should confirm this.
At that point I again run the vacuum pump to pump the system down again for any remaining air or moisture and then break vacuum with R12 (or R134a) refrigerant after making absolute sure I have purged any and all air from the lines when disconnecting the vacuum pump and connecting the refrigerant. Remember that you need to even consider the gage manifold itself as a reservoir for a small amount of air............so I blow a bit of refrigerant into the manifold with the red and blue valves still closed to help purge out any chance of air. I do this a few times, blowing thru the refrigerant yellow line with refrigerant to to remove the air.
I then add about 1 can or 1 pound of refrigerant. Change cans and purge lines again if using small cans. Then I start the car, activvate AC and run RPM up to 1500, and slowly add remaining refrigerant. I use both weight of refrigerant added as well as look for absence of bubbles in the drier sight glass.
I also monitor hi and low AC pressures as well as temperature coming from the AC vents in the car cabin.
I can talk you through any and all of these steps if you want. PM for my phone number.
To do the job correctly, you need a Chevrolet Service Manual, good vacuum pump, refrigerant, proper oil, manifold gage set that is reliable, small thermometer for AC vents, a helper/friend to assist, and borrow or buy a refrigerant electronic leak detector for troubleshooting. Also some SNOOP leak check solution. Also new o-rings for any time you break a connection or suspect a o-ring leak.
Hope this helps.
Larry
Sometimes I jump the compressor to run for 5 or 6 seconds to get the system to balance after 1 can. It helped on a friends 67.
05-27-2018, 09:01 PM
#16
Safety Car
Pop:
OP said in opening paragraph that his AC system has been dead for years.....maybe even decades...........drier replacement is good insurance after all this time.
I agree that if you have cylinder dry nitrogen, use it to break vacuum as well as for all pressure tests.. But most folks simply don't have this available to them. My recommendation was to replace drier and re-vacuum system in a short period of time. Moisture intrusion should be low and re-vacuum will pull it back out. Drier is good for I believe 1-2 tablespoons of water removal. But unless OP is doing this in the rain, I do not feel it will harm him or his system for this brief period. But if he can find dry nitrogen, that is what he should use.
Pop and Dan:
I do appreciate your comments..........as I continue to learn as well.
Larry
OP said in opening paragraph that his AC system has been dead for years.....maybe even decades...........drier replacement is good insurance after all this time.
I agree that if you have cylinder dry nitrogen, use it to break vacuum as well as for all pressure tests.. But most folks simply don't have this available to them. My recommendation was to replace drier and re-vacuum system in a short period of time. Moisture intrusion should be low and re-vacuum will pull it back out. Drier is good for I believe 1-2 tablespoons of water removal. But unless OP is doing this in the rain, I do not feel it will harm him or his system for this brief period. But if he can find dry nitrogen, that is what he should use.
Pop and Dan:
I do appreciate your comments..........as I continue to learn as well.
Larry