Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

A?C Freon, can you tell if this is r-12

Thread Tools
 
Search this Thread
 
Old 06-22-2019, 07:54 AM
  #1  
Supreme Member
Thread Starter
 
vinny R's Avatar
 
Join Date: May 2015
Location: Florida
Posts: 1,708
Received 239 Likes on 185 Posts
Car: 1991 Z28
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3:42 Auburn
A?C Freon, can you tell if this is r-12

I have a 91 and was out last night with the top up and the A/C on and it felt like it could use some freon. It gets colder when driving and warms a little while sitting at the light.
Is there anyway to tell if this is the original system or has one of the previous 7 owners replaced something. The label on the compressor is there but the writing is all worn off. No label on the drier either. There is just that blue cap on the drier. Is that indicating by color the type of freon?


Old 06-22-2019, 10:21 AM
  #2  
Supreme Member

iTrader: (1)
 
sofakingdom's Avatar
 
Join Date: Sep 2005
Posts: 26,051
Received 1,672 Likes on 1,269 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: A?C Freon, can you tell if this is r-12

Take the cap off and post up a good clear close-up photo of the service valve.

Looks to me like it has a R-134a adapter on it but it's hard to be sure.

I'd recommend getting rid of that "breather" on the valve cover and hooking the PCV back up right, it'll help keep the oil cleaner, and eliminate the "old car" oil/gasoline/exhaust smell coming from the engine.

Last edited by sofakingdom; 06-22-2019 at 10:26 AM.
Old 06-23-2019, 06:35 AM
  #3  
Supreme Member
Thread Starter
 
vinny R's Avatar
 
Join Date: May 2015
Location: Florida
Posts: 1,708
Received 239 Likes on 185 Posts
Car: 1991 Z28
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3:42 Auburn
Re: A?C Freon, can you tell if this is r-12

Here are the pics. I think you are right as always Sofa. It looks like the quick release fitting on the R-134 hose I have.
Man I like my little K&N breather! I do have my original parts and I did put my original VC's back on so maybe I will hook it back up.





Old 06-23-2019, 08:11 AM
  #4  
Supreme Member

iTrader: (1)
 
sofakingdom's Avatar
 
Join Date: Sep 2005
Posts: 26,051
Received 1,672 Likes on 1,269 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: A?C Freon, can you tell if this is r-12

Yup, that's definitely a 134a adapter... it's been "converted". To what extent, or how diligently, is anybody's guess.

Ideally, they would have replaced the compressor, rubber/plastic lines, all O-rings, accumulator/dryer, and orifice tube. Who knows whether they did all of that.

In any case, try adding a can of cold juice, and see if it gets better.
Old 06-23-2019, 09:10 AM
  #5  
Moderator

 
Vader's Avatar
 
Join Date: Jan 2000
Posts: 19,350
Received 216 Likes on 177 Posts
Re: A?C Freon, can you tell if this is r-12

All soft lines should have been replaced with barrier style hoses, since the original A/C hoses were not.
Old 06-23-2019, 11:08 AM
  #6  
Supreme Member

iTrader: (1)
 
sofakingdom's Avatar
 
Join Date: Sep 2005
Posts: 26,051
Received 1,672 Likes on 1,269 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: A?C Freon, can you tell if this is r-12

should have been replaced
Indeed... but who knows. I can't tell you how many I've seen where somebody just put the adapter on the port and started adding whatever, without ANY proper preparation at all. It usually doesn't end well.
Old 06-23-2019, 11:59 AM
  #7  
Member
iTrader: (11)
 
Ty92Z's Avatar
 
Join Date: Feb 2015
Location: Fayetteville, NC
Posts: 340
Received 11 Likes on 8 Posts
Car: 1992 Z28 1991 RS
Engine: LB9 LO3
Transmission: 5 speeds
Re: A?C Freon, can you tell if this is r-12

Is any new hose going to be barrier style? How can you tell? Going to be refreshing my AC system soon and want to make sure I get the proper parts. Vinny, that is an aftermarket Delco compressor, not the original.
Old 06-23-2019, 12:02 PM
  #8  
Supreme Member

iTrader: (1)
 
sofakingdom's Avatar
 
Join Date: Sep 2005
Posts: 26,051
Received 1,672 Likes on 1,269 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: A?C Freon, can you tell if this is r-12

You can just look inside the hose. If it seems to be lined with a layer of hard plastic, it's the barrier type.
Old 06-29-2019, 07:01 AM
  #9  
Supreme Member
Thread Starter
 
vinny R's Avatar
 
Join Date: May 2015
Location: Florida
Posts: 1,708
Received 239 Likes on 185 Posts
Car: 1991 Z28
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3:42 Auburn
Re: A?C Freon, can you tell if this is r-12

Thanks guys for the info. I did add about 3/4 of a can and all seems well and cool. When I took off the service cap I heard a slight pssst so I think the Schroeder valve might be leaking slightly, but I did notice a rubber seal in the cap so maybe this is normal. I don't use the A/C much and have not had a problem with it so for this purpose I will assume (we all know what this means) that whoever did the conversion did an adequate job.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jas89TTA
Tech / General Engine
8
06-29-2021 07:29 AM
jaredjames
Cooling
6
03-08-2004 03:41 PM
92blue
Tech / General Engine
22
08-28-2002 01:40 PM
soulbounder
Tech / General Engine
4
11-25-2001 03:30 PM
dtpmike
Tech / General Engine
9
11-28-2000 12:03 AM



Quick Reply: A?C Freon, can you tell if this is r-12



All times are GMT -5. The time now is 04:43 PM.