Air Cond. Conversion Questions
Thread Starter
Instructor
Joined: Jun 2000
Posts: 148
Likes: 0
From: Chatham Ontario
Air Cond. Conversion Questions
The other day we had our first 80 degree day, and it got me to thinking that the air in my 1980 doesn't really work all that well anymore. It seems that most of the shops in the area want to do a conversion, do to the R112 - R134A thing. What are the components that must be replaced? And, are any of the existing parts compatible? What else should I know before handing over my cash? Thanks.
Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: Air Cond. Conversion Questions (RonnyV1980)
IMO, 134A is a last resort. There are several replacement that cool just as well as R12 and cost little to nothing to switch over.
Drifting
Joined: Aug 2002
Posts: 1,731
Likes: 22
From: Marietta Ga.
Re: Air Cond. Conversion Questions (RonnyV1980)
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: Air Cond. Conversion Questions (RonnyV1980)
What is the problem with the current unit? If it is lack of cold air volume, the problem may just be the accumulated stuff (leaves, twigs, feathers, cat hair, etc) that is covering the evaporator. Clearing this stuff out will let the air flow over the evaporator. The under dash plumbing/vents sometimes are out of position, and the AC cools the underside of the dash.
In the AC/Heater box some of the seals may have deteriorated and air control doors may be out of alignment.
In any case, sure to use a reputable shop that can TEST what the refrigerant gas is. With the high cost of R-12 some suppliers (non reputable) are using propane, etc.
Seals on the hose connections are different between R-12 and R134. Also the refrigerant dryer will have to be changed as the system is opened up to the atmosphere when changing the seals. The shop should put a vacuum on the system to remove the air (water vapor) BEFORE filling with the new refrigerant.
I'd check the simple - cheap stuff first.
In the AC/Heater box some of the seals may have deteriorated and air control doors may be out of alignment.
In any case, sure to use a reputable shop that can TEST what the refrigerant gas is. With the high cost of R-12 some suppliers (non reputable) are using propane, etc.
Seals on the hose connections are different between R-12 and R134. Also the refrigerant dryer will have to be changed as the system is opened up to the atmosphere when changing the seals. The shop should put a vacuum on the system to remove the air (water vapor) BEFORE filling with the new refrigerant.
I'd check the simple - cheap stuff first.
Thread Starter
Instructor
Joined: Jun 2000
Posts: 148
Likes: 0
From: Chatham Ontario
Re: Air Cond. Conversion Questions (RonnyV1980)
A friend told me I would be able to reuse the condensor, but would need different lines and another pump. Has anyone done this, and if so, what were some of the pitfalls?
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: Air Cond. Conversion Questions (RonnyV1980)
My 69 works great with R134a in it. I just changed the drier and the oil. I used ester oil. Just make sure the system is not overcharge when converting to R134a. That is the most common reason people are not happy with R134a. It is very sensitive to the correct charge.
Le Mans Master
Joined: Nov 2000
Posts: 5,210
Likes: 104
From: Fort Worth TX
St. Jude Donor '06
Father & Son St. Jude Donor '09
Re: Air Cond. Conversion Questions (RonnyV1980)
To ensure 134A is as efficient as R-12, the control of the pressure in your evaporator must be adjusted to the slight differences in 134A. I'm not sure how your system controls the pressure, but I think it's through an orifice tube. If so, I think you'll need a replacement tuce calibrated for 134A.
In a nutshell, ask the shop how they'll calibrate your system for 134A. If they say no changes are needed, go somewhere else . . . they aren't experts. I have three books that all discuss heat transfer of the various coolants available and the pressure in the evaporator must meet the requirements for each specific coolant to achieve optimum cooling. :yesnod:
In a nutshell, ask the shop how they'll calibrate your system for 134A. If they say no changes are needed, go somewhere else . . . they aren't experts. I have three books that all discuss heat transfer of the various coolants available and the pressure in the evaporator must meet the requirements for each specific coolant to achieve optimum cooling. :yesnod:
