I am thinking of removing the AC from my car. It only blows slightly cool air now anyway. I will also need to polish it if I keep it, and that's going to be a bitch. So I am really thinking of taking it off. If I was to do this, and then say a couple of years from now I decide I really want it back on there, can I put it back on and get it recharged? Or am I SOL?
Will AC work after removal?
- Thread starter 9 Deuce GT
- Start date
If you remove the A/C compressor, when you re-install it, you will need to flush the system and install a a new accumulator/dryer (aluminum canister mounted on the firewall). The accumulator/dryer is about $75 last time I checked. The system will need to be vacuumed down & recharged with R134.
GearHd6
Member
Whats the point of the vacuum? I've recharged systems that were opened before without a vacuum and they worked. What kind of vent temps can be expected from the R134 conversion? I seem to be able to get a best of 48 degrees with mine.
You need to pull a vacuum on the system because the refrigerant cycle is based on pressure. If it's not vacuumed out it will work but it will not work as well as it should. You also need to get any moisture/debris (like dust or possible creepy crawlies) out of the system so that it doesn't eat the compressor up or clog the orifice on the expansion valve. You also need to get the R12 oil out of the system since it doesn't mix with the R134 correctly and can lead to compressor failure due to lack of oil. My A/C pulls about 50 degrees since the conversion.
GearHd6
Member
Bladez5_0 said:
So you're pulling roughly the same vent temps as me then. I guess thats about the norm for the conversion then?
PuterAmI
Member
Nope.GearHd6 said:
I get them colder than that.
Both of mine I have at 42 degrees on a 93 ambient.
GearHd6
Member
PuterAmI said:
So whats the key to getting the low temp? I never vacuumed it and im getting 48 degrees at 40 psi and 90 degree ambient.
65ShelbyClone
Founding Member
jrichker said:
Ditton on all of that.
The point of vacuuming the system is not only to evaporate and remove moisture, but to remove the air itself so an absolutely full charge of tetrafluoroethane can be put in. About 28 in/Hg vacuum or more for 30min is needed.
I did a hokey 134A conversion on my '89 GT and I wished I'd done it sooner. Even in 90* weather it would make my ears so cold I got a headache.
PuterAmI
Member
GearHd6 said:
Charging into a vacuum increases performance. Less air, more refrigerant for a given pressure. I also do more than the kit that people get from the auto parts stores that technicians call "death kits".
Fox R134A Conversion
pb_paulie_b
Founding Member
Compressing air leads to heat. Find a guy that does residential A/C and heating. They normally have the vacuum you need on their truck and save the dough you were gonna pay a shop to do it.
Here's a cheap solution, maybe cheaper than paying to have it done. My current vacuum pump is a refrigerator hermetic unit (motor & compressor in one unit). It was a freebe from a local used appliance store. I bolted it down to a piece of plywood & soldered a 1/4" flare fitting on the suction line. It works great, pulls 29" of vacuum in about 10 minutes or less. I have used it several times and have had excellent results.pb_paulie_b said:
pb_paulie_b
Founding Member
ALMOST STOCK
Founding Member
I’m assuming (and we all know what that means) that the reason you need to pull a vacuum is because this is the only way to remove refrigerant and oil when the compressor is in it’s normal position but if it were out of the car and draining for 2 yrs would you really have to pull a vacuum?
I’m no AC expert and I’m not claiming to be believe me, but if 9 Deuce GT is going to have his compressor out of the car for possibly 2 yrs why couldn’t he just put some caps on the discharge and suction ends of the compressor to keep out any contaminates out, prop the compressor so that the old oil and refrigerant would drain toward the caps.
Then every once and awhile when he thinks about it in the next 2 yrs turn the clutch pulley a couple of turns and then remove the old accumulated oil and refrigerant that has collect at the caps?
I’m no AC expert and I’m not claiming to be believe me, but if 9 Deuce GT is going to have his compressor out of the car for possibly 2 yrs why couldn’t he just put some caps on the discharge and suction ends of the compressor to keep out any contaminates out, prop the compressor so that the old oil and refrigerant would drain toward the caps.
Then every once and awhile when he thinks about it in the next 2 yrs turn the clutch pulley a couple of turns and then remove the old accumulated oil and refrigerant that has collect at the caps?
The vacuum removes the air & moisture. The air trapped in a system displaces refrigerant. That means you can't get a full charge of refrigerant in the system without exceeding the safety spec for max head pressure. Not only that, but the A/C process depends on expanding a hot liquid into a cold gas. Air will not compress enough to liquify in an auto A/C system.ALMOST STOCK said:
Moisture in the system combines with heat, air & refrigerant to make acid which destroys the A/C system from the inside out.
A vacuum does not remove the oil, you need a flush to do that.
Even if he found a way to make some airtight caps he would still need to vacuum out the system due to the remaining refrigerant and oil in the system. Regardless of what the retrofit kits at WalMart say R12 equipment is not compatible with R134. The oil used with R12 doesn't mix with R134 and therefore isn't carried throughout the system. If you put the correct amount of R134 oil into your A/C system without flushing all the R12 oil out it leaves you overcharged with oil and undercharged with refrigerant which means that your A/C doesn't cool as well as it could. You could also end up hydraulically locking the compressor and oil (like water) is uncompressable which has a tendency to break stuff then. Plus some orings used with R12 react to R134 in a bad way.
65ShelbyClone
Founding Member
jrichker said:Here's a cheap solution, maybe cheaper than paying to have it done. My current vacuum pump is a refrigerator hermetic unit (motor & compressor in one unit).
I have one of those too. I flared the copper tubes and have AN fittings on there. My compressor came out of a one of those beverage coolers from a convenience store. The problem I have is it gets down to about 28in/Hg and then bypasses or something and the vacuum declines until it starts pumping again. It also starts getting hot.
While we're on the subject, I have a few question of my own:
What is required to do a flush? Both of my cars are going to get 134a and I want to do the conversion right the first time.
Also, aren't there refrigerants other than R12 and 134a that could be used in automotive systems?
PuterAmI
Member
Bladez5_0 said:
It is a common misconception that a vacuum draws out the oil.
It does not. jrichker said that 5 minutes before you did.
PuterAmI
Member
Either read jrichker's writeup, or see mine where I describe how to flush and convert.65ShelbyClone said:
Fox R134A Conversion
Yes. They are called "alternative refrigerants".65ShelbyClone said:
Please see the below webpage.
EPA: Choosing and Using Alternative Refrigerants
PuterAmI- While jrichker was posting I was writing the post you quoted so I didn't see his until after I had posted. I agree with you that if the system is correctly filled vacuuming the system will not remove oil but will remove some oil if the system has been overfilled with oil. Tire Kingdom got 9oz of oil out of my old honda civic when they vacuumed it out. It worked a lot better then.
Similar threads
