R-12 how much?
Thread Starter
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
R-12 how much?
how many oz does the R-4 1979 A/C system take? I have several bottles of R-12 sitting around....
I vacuumed the system for several hours and it is holding at -20PSI
or what should the high side and the low side read (PSI) when on? is the low side 60psi like home?
thx..
I vacuumed the system for several hours and it is holding at -20PSI
or what should the high side and the low side read (PSI) when on? is the low side 60psi like home?
thx..
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
The original sticker from my late model '77 shows 3.0? lbs.. I can't tell if it is 3.00 or 3.08lbs. I don't know if a '79 is exactly the same but should be close. Pressures will vary with outdoor ambient and engine rpm. I normally use the approx. number of ozs. while checking the temp. at registers. Usually 45-50 degres is normal and will cool the car. The small cans are 14ozs.. So if it is 3.08 lbs. will be 49.28 ozs. = 3.52 14oz. cans. mike...
Last edited by mds3013; Jul 17, 2010 at 01:17 PM. Reason: small cans are 14ozs.
Safety Car
Joined: Jun 2004
Posts: 4,372
Likes: 223
From: Beecher Illinois
I vac'd and refilled all 4 of my Vettes last summer. 3 12oz cans should be plenty.
One of them leaked through the main O-rings in the compressor and had to re-do it this past month.
Used a 30lb tank this time and put in just over 2 lbs weight. About 36oz which is exactly what 3 12oz cans weigh.
The chart I've been using for years.....
outside temp70...low23-28...high135-170
outside temp80...low23-29...high170-205
outside temp90...low26-35...high205-245
outside temp100..low31-40...high245-285
One of them leaked through the main O-rings in the compressor and had to re-do it this past month.
Used a 30lb tank this time and put in just over 2 lbs weight. About 36oz which is exactly what 3 12oz cans weigh.
The chart I've been using for years.....
outside temp70...low23-28...high135-170
outside temp80...low23-29...high170-205
outside temp90...low26-35...high205-245
outside temp100..low31-40...high245-285
Thread Starter
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
The original sticker from my late model '77 shows 3.0? lbs.. I can't tell if it is 3.00 or 3.08lbs. I don't know if a '79 is exactly the same but should be close. Pressures will vary with outdoor ambient and engine rpm. I normally use the approx. number of ozs. while checking the temp. at registers. Usually 45-50 degres is normal and will cool the car. The small cans are 12ozs.. So if it is 3.08 lbs. will be 49.28 ozs. = 4.1 12oz. cans. mike...
I vac'd and refilled all 4 of my Vettes last summer. 3 12oz cans should be plenty.
One of them leaked through the main O-rings in the compressor and had to re-do it this past month.
Used a 30lb tank this time and put in just over 2 lbs weight. About 36oz which is exactly what 3 12oz cans weigh.
The chart I've been using for years.....
outside temp70...low23-28...high135-170
outside temp80...low23-29...high170-205
outside temp90...low26-35...high205-245
outside temp100..low31-40...high245-285
One of them leaked through the main O-rings in the compressor and had to re-do it this past month.
Used a 30lb tank this time and put in just over 2 lbs weight. About 36oz which is exactly what 3 12oz cans weigh.
The chart I've been using for years.....
outside temp70...low23-28...high135-170
outside temp80...low23-29...high170-205
outside temp90...low26-35...high205-245
outside temp100..low31-40...high245-285
thank you so much guys!!!i have 2 cans in right now and it is cool.... so i will monitor the pressure and put in the 3rd
first time the A/C has worked in 20 years
first time it has had any A/C equipment in it for 10 years.....
i am so stocked!!! and its 105 here!!
thx again.. Paul
