my a/c sucks
Thread Starter
Intermediate
Joined: May 2006
Posts: 49
Likes: 0
From: Tyrone GA
my a/c sucks
This car is a 1992 that was converted to r134 before I bought it. It also appears that the evaporator was already replaced (I checked to make sure it was not clogged). It just seems that the air comming from the vents is not all that cold.
So my question is does any one know what parts are different between the earlier r12 cars and the latter r134 cars?
I have read that the condensor is different and I it probally needs to be replaced due to alot of road damage, so I thought I might replace all the r12 parts with r134 ones at the same time.
So my question is does any one know what parts are different between the earlier r12 cars and the latter r134 cars?
I have read that the condensor is different and I it probally needs to be replaced due to alot of road damage, so I thought I might replace all the r12 parts with r134 ones at the same time.
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
I have my R12 system charged with R134a (after a complete vaccum and oil swap..etc..etc..) and my temps at the duct with the AC at MAX engine RPM at 2000 is about 48*
Sounds like you may be heavy or light on the refirigerent.. take it to a good shop (or hook up a set of gauges) and have a look at it!
Sounds like you may be heavy or light on the refirigerent.. take it to a good shop (or hook up a set of gauges) and have a look at it!
Burning Brakes
Joined: Nov 2005
Posts: 1,211
Likes: 2
From: Dumas Arkansas
Is your Blower Motor working for sure? Make sure by raising the hood with the a/c being on 10, put your hand on the blower motor or just listen to it. I know you have the auto-climate control without a shadow of a doubt.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Repalcing the condenser and evaporator would just be a waste of money. They are nothing but basic heat exchangers and the same parts no matter R-12 or R-134. Restricted airflow thru either can cause problems, so if the evap is clean then check the condenser and clean if necessary. Actually though it sounds more like a low freon charge than anything else.
Racer
Joined: Jan 2006
Posts: 473
Likes: 7
From: Houston Texas
[QUOTE=aminnich;1560156262]Repalcing the condenser and evaporator would just be a waste of money. They are nothing but basic heat exchangers and the same parts no matter R-12 or R-134.
Wrong.
From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.
Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf
Page 26 of manual quote:
System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.
http://www.epa.gov/ozone/title6/609/609.html
Wrong.
From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.
Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf
Page 26 of manual quote:
System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.
http://www.epa.gov/ozone/title6/609/609.html
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
All of the above - but there are a couple of things you can do to make it work better: 1: Find out what the operating pressures are and if it's got more than 30 PSI on the low side at 80 degree ambient, get some gas out of it. 26 to 28 PSI will drop your vent temps 5 or 6 degrees. 2. Get you fans (PCM) reprogrammed to crank on when the a/c pressure switch indicates 180 to 200 psi. That will help to keep the high side at no more than 2.2 times ambient or whatever the air temp is at the condensor. 3. Reduce the cycling threshold to 22.5 psi. Get it on max and pull the blower motor connector. That will drop the low and the compressor will cycle off at whatever is cranked into the Low Pressure Switch (should be 25psi for R12). Remove the harness from the Low Pressure Switch and turn the adjustment screw between the terminals counterclockwise 1/2 turn. Hook it back up and retest. Keep testing and turning the screw 1/2 turn at a time until the compressor kicks off at 22.5 psi. Most take no more that 1 full turn.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
[QUOTE=davidnclearlaketx;1560157468]
Yes! You are right! No! I am not wrong. I don't believe she will find an
R134A Condenser for the 92, nor an R143a evaporator. She says the system was already converted so I am assuming the accumalator, seals, orifice tube, etc. were changed at that time. The purpose of my response was to try to save her from buying parts that will not fix the problem. Then again it is her car and her wallet.
Repalcing the condenser and evaporator would just be a waste of money. They are nothing but basic heat exchangers and the same parts no matter R-12 or R-134.
Wrong.
From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.
Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf
Page 26 of manual quote:
System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.
http://www.epa.gov/ozone/title6/609/609.html
Wrong.
From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.
Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf
Page 26 of manual quote:
System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.
http://www.epa.gov/ozone/title6/609/609.html
R134A Condenser for the 92, nor an R143a evaporator. She says the system was already converted so I am assuming the accumalator, seals, orifice tube, etc. were changed at that time. The purpose of my response was to try to save her from buying parts that will not fix the problem. Then again it is her car and her wallet.
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Thread Starter
Intermediate
Joined: May 2006
Posts: 49
Likes: 0
From: Tyrone GA
Thank You for all the responses to the post. I do want to say that julie is my wifes name and 32 is the car I sold to buy the vette so I am actually a he. Actually I sold the 32 because I did not think I was going to have a job. (I work for a major airline as mech)
As I mentioned in the original post the condensor is pretty beat up from road debris so I thought I would replace it anyway. If the r134 condensor is a bolt in Id just replace the old one with a later one and adjust the switch. Anyone have experience doing this?
As I mentioned in the original post the condensor is pretty beat up from road debris so I thought I would replace it anyway. If the r134 condensor is a bolt in Id just replace the old one with a later one and adjust the switch. Anyone have experience doing this?
Race Director
Joined: Dec 2002
Posts: 13,348
Likes: 233
From: SCMR Rat Pack'r Charter Member..Great Bend KS
I'm surprised that so many convert from R12 to R134.
R12 is still available and is so much more efficient... in a system designed for it...than R134 that the extra cost of the R12 is well worth it.
That's my opinion, anyway.
I mention this to show those facing this situation that converting to R134 is an OPTION, not mandatory.
Larry
code5coupe
__________
Not easily impressed....
R12 is still available and is so much more efficient... in a system designed for it...than R134 that the extra cost of the R12 is well worth it.
That's my opinion, anyway.
I mention this to show those facing this situation that converting to R134 is an OPTION, not mandatory.
Larry
code5coupe
__________
Not easily impressed....
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Rocco is correct in that R-12 is a more efficient refrigerant and will give better vent temeperatures. It was/is environmentally a hazard, otherwise it would still be the refrigerant of choice.
Blower motor not moving enough air has been discussed here before. The usual fix is to pull the motor off to access the evaporator and clean the evaporator.
Julie is a guy! Good to know that. I did check your profile, but wasn't sure. Sorry.
Blower motor not moving enough air has been discussed here before. The usual fix is to pull the motor off to access the evaporator and clean the evaporator.
Julie is a guy! Good to know that. I did check your profile, but wasn't sure. Sorry.
Thread Starter
Intermediate
Joined: May 2006
Posts: 49
Likes: 0
From: Tyrone GA
No offense taken although Julie is my wife. Thats our online name that we use for alot of stuff.
I did check the evaporator and it was clear. I was going to take the heater box apart to clean it but one of threads in the frame for the brace bolts is stripped. This is how I know the evap has been replaced.
I still wonder at how well the r134 conversion was done. I have found alot of evidence of shoddy maint. work on the car. That is why I am thinking of starting all over with the a/c system (amongst other things)
I did check the evaporator and it was clear. I was going to take the heater box apart to clean it but one of threads in the frame for the brace bolts is stripped. This is how I know the evap has been replaced.
I still wonder at how well the r134 conversion was done. I have found alot of evidence of shoddy maint. work on the car. That is why I am thinking of starting all over with the a/c system (amongst other things)
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
No offense taken although Julie is my wife. Thats our online name that we use for alot of stuff.
I did check the evaporator and it was clear. I was going to take the heater box apart to clean it but one of threads in the frame for the brace bolts is stripped. This is how I know the evap has been replaced.
I still wonder at how well the r134 conversion was done. I have found alot of evidence of shoddy maint. work on the car. That is why I am thinking of starting all over with the a/c system (amongst other things)
I did check the evaporator and it was clear. I was going to take the heater box apart to clean it but one of threads in the frame for the brace bolts is stripped. This is how I know the evap has been replaced.
I still wonder at how well the r134 conversion was done. I have found alot of evidence of shoddy maint. work on the car. That is why I am thinking of starting all over with the a/c system (amongst other things)
Instructor
Joined: Jan 2007
Posts: 131
Likes: 0
From: Silver Spring MD
Who did the original swap? I tried it on a Saturn a long time ago, and to no avail because I need to vacuum the lines and then charge the system. my quick job resulted in minimal but noticeable cooling. (wasnt worth sinking into the pockets to freeze the beater)
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
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Make sure your system isn't cross-contaminated with traces of R12 and R134a oil and refrigerant.
If that's the case, your A/C won't cool well at all. Take it to an auto HVAC shop and have it tested.
They can evacuate the system, then refill with the proper oil/refrigerant charge.
If that's the case, your A/C won't cool well at all. Take it to an auto HVAC shop and have it tested.
They can evacuate the system, then refill with the proper oil/refrigerant charge.
Thread Starter
Intermediate
Joined: May 2006
Posts: 49
Likes: 0
From: Tyrone GA
Thread Starter
Intermediate
Joined: May 2006
Posts: 49
Likes: 0
From: Tyrone GA
UPDATE
A/C kicks but now.
As suncr sugested it was low on freon. I did watch the mech service it so I should be able to do it myself next time.
He filled it to 85% of what the r12 charge should be, this produced approx 35psi low and 125psi high side. He also did a leak chk and did not find any so it makes me wonder why it was low. Again I do not know who converted,why(evap leak?) and how professional that person was(no ident stickers, r12 fitting still on high side). Anyway it works well and I see no reseaon to mess wit it further unless there is a leak.
A/C kicks but now.
As suncr sugested it was low on freon. I did watch the mech service it so I should be able to do it myself next time.
He filled it to 85% of what the r12 charge should be, this produced approx 35psi low and 125psi high side. He also did a leak chk and did not find any so it makes me wonder why it was low. Again I do not know who converted,why(evap leak?) and how professional that person was(no ident stickers, r12 fitting still on high side). Anyway it works well and I see no reseaon to mess wit it further unless there is a leak.
Racer
Joined: Jan 2007
Posts: 416
Likes: 2
From: Aquilla TX
In TEXAS it gets quite hot during the summer, my 95 vette shows no stickers so I am not sure what it has in it but it will put frost on your legs and arms if you run it long. The wife says you could "hang meat" in the vette when the air is on. Glad you got yours fixed.
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