How do you change an A/C compressor?

[dgreet77]

Re: How do you change an A/C compressor?

^ok sounds good to me....i just thought otherwise....thats fine :)....and if you are needing to charge up an old R-12 system i know you can use a liquified petroleum something-or-other, dont ask me the proper term for it, but it comes in a large tank that looks just like propane tank...i know this is out there because we have some...and it isnt just a huge tank of R-134A...

[Firebirdkid96]

Re: How do you change an A/C compressor?

Well I've seen alot of discussion on this and having replaced now three compressors I feel the need to chime in.

First, evacuating the system.

Yes, before you refill the system it needs to be evacuated. but we're not talking about evacuating it of refrigerant. Odds are if you're replacing your compressor, the shaft seal was leaking the r-134a and so you aren't dealing with it anyway. You evacuate the system AFTER you've installed the new compressor to get any moisture and little debris out of the lines, the receiver-dryer...etc. To do so you'll need an a/c manifold which is a device with two gauges and three lines. One line is your high pressure fitting one is your low pressure. The high pressure side is the side with your receiver-dryer and condenser, the low pressure side has your evaporator. you cant mix them up. the center line is used as an interface for refilling, evacuating, whatever you're putting in or taking out of the system. To evacuate the system, the easiest way is to go to harbor freight tools website and order an "a/c vacpump". you'll also need an air compressor top do this. IT IS VERY IMPORTANT THAT YOU NOT SKIP THIS STEP. YOU NEED TO GET EVERYTHING OUT OF THERE. if not you'll be replacing your compressor again lol. trust me.
here's the link.
http://www.harborfreight.com/cpi/cta...emnumber=96677

and this is the manifold
http://www.harborfreight.com/cpi/cta...emnumber=92649

next thing you need to remember is that before you put the compressor back on, you need to fill it with a/c compressor oil designed for r-134a compressors. you can get this at any auto parts store.

as far as refilling the system, you'll refill it with R-134a, which is not a restricted gas. I believe the sticker on v6's calls for 1.68 lbs of refrigerant, I recommend keeping it at 1.5 because if you overfill (which is easy to do), the pressure will become too high, and blow the seal. you can also fill it with a special dye that shows up under UV light so you can tell if it's ever leaking.i'll do a writeup on this when I replace my compressor in about a week. :tup:

and for the discussion on r-12 and r-134a.... freon is a term copyrighted by the dupont company as a trade for their chlorofluorocarbon and hydrochlorofluorocarbon refrigerents.
R-12, commonly known by it's freon-12 brand name is a restricted gas because of it's reactive nature, and it is a methane with two chlorine atoms and two fluorine atoms, making it highly detrimental to our O-Zone because it is saturated. You need a license to purchase R-12 and it's being phased out of use in automotive applications. Now we use R-134A, also know as Freon 134-a (see how this works lol, its like ppl calling tissues kleenex) because while it is still not safe, it does not deplete the ozone because it is hydrated by the presence of two hydrogen atoms. HOWEVER, R-134a is still dangerous because it is an asphyxiant. dont breathe it in lol.

here's a pic of how the system works.



hope this helps!

[Atreus21]

Re: How do you change an A/C compressor?

no, its not dangerous, but you should have a shop properly take the refrigerant out (although they probably just do that dgreet said.

why are you changing the compressor by the way?

and there is NO WAY it would be worth paying $1200 for someone to do that.. once you do it yourself you will realize how simple it is, and want to kick yourself for even thinking of taking it to a shop




you are correct, our cars use R-134a, you can buy a kit to recharge your system at any parts store

there is two sides to the ac system, the high and low sides.

im not sure which is which, but there is a cap on the receiver/dryer which is the one you recharge the system with, and there is another in front of the radiator, they both have black caps on them.

i used one of these kits to recharge my car after i installed my compressor, and my ac comes out just as cold as my fathers car, which has never had any ac work done to it, he said it may even be a bit colder

I'm changing the compressor because the air isn't cold anymore. I brought it to the shop, and the told me the compressor was busted.

[Atreus21]

Re: How do you change an A/C compressor?

Well I've seen alot of discussion on this and having replaced now three compressors I feel the need to chime in.

First, evacuating the system.

Yes, before you refill the system it needs to be evacuated. but we're not talking about evacuating it of refrigerant. Odds are if you're replacing your compressor, the shaft seal was leaking the r-134a and so you aren't dealing with it anyway. You evacuate the system AFTER you've installed the new compressor to get any moisture and little debris out of the lines, the receiver-dryer...etc. To do so you'll need an a/c manifold which is a device with two gauges and three lines. One line is your high pressure fitting one is your low pressure. The high pressure side is the side with your receiver-dryer and condenser, the low pressure side has your evaporator. you cant mix them up. the center line is used as an interface for refilling, evacuating, whatever you're putting in or taking out of the system. To evacuate the system, the easiest way is to go to harbor freight tools website and order an "a/c vacpump". you'll also need an air compressor top do this. IT IS VERY IMPORTANT THAT YOU NOT SKIP THIS STEP. YOU NEED TO GET EVERYTHING OUT OF THERE. if not you'll be replacing your compressor again lol. trust me.
here's the link.
http://www.harborfreight.com/cpi/cta...emnumber=96677

and this is the manifold
http://www.harborfreight.com/cpi/cta...emnumber=92649

next thing you need to remember is that before you put the compressor back on, you need to fill it with a/c compressor oil designed for r-134a compressors. you can get this at any auto parts store.

as far as refilling the system, you'll refill it with R-134a, which is not a restricted gas. I believe the sticker on v6's calls for 1.68 lbs of refrigerant, I recommend keeping it at 1.5 because if you overfill (which is easy to do), the pressure will become too high, and blow the seal. you can also fill it with a special dye that shows up under UV light so you can tell if it's ever leaking.i'll do a writeup on this when I replace my compressor in about a week. :tup:

and for the discussion on r-12 and r-134a.... freon is a term copyrighted by the dupont company as a trade for their chlorofluorocarbon and hydrochlorofluorocarbon refrigerents.
R-12, commonly known by it's freon-12 brand name is a restricted gas because of it's reactive nature, and it is a methane with two chlorine atoms and two fluorine atoms, making it highly detrimental to our O-Zone because it is saturated. You need a license to purchase R-12 and it's being phased out of use in automotive applications. Now we use R-134A, also know as Freon 134-a (see how this works lol, its like ppl calling tissues kleenex) because while it is still not safe, it does not deplete the ozone because it is hydrated by the presence of two hydrogen atoms. HOWEVER, R-134a is still dangerous because it is an asphyxiant. dont breathe it in lol.

here's a pic of how the system works.



hope this helps!

Okay great. I'll order the vacpump and the manifold, but I don't understand what the manifold is for. Also, how do you add the oil to the compressor?

I'm sorry, I'm quite new to this, so please excuse the dumb questions. I haven't bought the compressor yet.

[Rob Bell]

Re: How do you change an A/C compressor?

Atreus, before you go changing the compressor, press in the valve on the receiver dryer (large can-like thing) and see if any gas comes out. If so, then you probably have a leaky seal. Buy one of those R134A re-charge kits with the included gauge. Make sure the R134A has "O-ring Conditioner" or "Seal Conditioner". Then use that kit to re-charge your system. The conditioner will swell up that leaky seal and probably solve your problem. I did this on one of my past cars and it worked great. Then you may just have to top it off a little bit each summer. If no gas comes out, then the system would have to be evacuated and all that. You probably only need to change the compressor if it's making horrible grinding noises or has seized. But if it just doesn't turn on, it's probably because of low system pressure.

[Atreus21]

Re: How do you change an A/C compressor?

Atreus, before you go changing the compressor, press in the valve on the receiver dryer (large can-like thing) and see if any gas comes out. If so, then you probably have a leaky seal. Buy one of those R134A re-charge kits with the included gauge. Make sure the R134A has "O-ring Conditioner" or "Seal Conditioner". Then use that kit to re-charge your system. The conditioner will swell up that leaky seal and probably solve your problem. I did this on one of my past cars and it worked great. Then you may just have to top it off a little bit each summer. If no gas comes out, then the system would have to be evacuated and all that. You probably only need to change the compressor if it's making horrible grinding noises or has seized. But if it just doesn't turn on, it's probably because of low system pressure.

Oh. Well, it's not making any nasty noises or anything. I'll give this a try. Thanks.

I suspect this will probably work, because when I brought the car in, the guys at the shop put refrigerant in, and it worked for about 3 months before getting hot again. Hell, even if it doesn't work, it'll be nice to have A/C for a New Orleans summer.

[Firebirdkid96]

Re: How do you change an A/C compressor?

Okay great. I'll order the vacpump and the manifold, but I don't understand what the manifold is for. Also, how do you add the oil to the compressor?

I'm sorry, I'm quite new to this, so please excuse the dumb questions. I haven't bought the compressor yet.

The manifold is what you hook to the hi and Low ac lines. Its like the interface from your a/c system to the vac pump, or a refill can. It's basically so you have gauges to monitor what you're doing with the vacuum and while you're recharging.

To fill the compressor with oil, you'll see two ports in the back, one is the inlet. Just pour it in until its full.

[cam98aro]

Re: How do you change an A/C compressor?

Okay great. I'll order the vacpump and the manifold, but I don't understand what the manifold is for. Also, how do you add the oil to the compressor?

I'm sorry, I'm quite new to this, so please excuse the dumb questions. I haven't bought the compressor yet.

personally i htink you are wasting your money on those things

just buy a kit with ac dye in it, and see where it is leaking out

mine was leaking out on the compressor.. not really sure where though

and there is a bolt on the compressor you take out to drain/refill the oil

[cam98aro]

Re: How do you change an A/C compressor?

To fill the compressor with oil, you'll see two ports in the back, one is the inlet. Just pour it in until its full.

this is wrong, you fill the new compressor up with the same amount of oil that came out of the old one

mine used around 3oz

[Firebirdkid96]

Re: How do you change an A/C compressor?

this is wrong, you fill the new compressor up with the same amount of oil that came out of the old one

mine used around 3oz

3 oz is about what it takes.

But why would you use the amount of oil in a broken, non-working compressor as a reference point? the oil can leak out just like the refrigerant and the measurement you'd be using would be wrong.

And how are you wasting money buying the tools that you need to do a job right. He asked how you switch the a/c compressor, not how to tell if the compressor is leaking. Obviously you want to check the compressor to make sure that's the problem before you replace it. and I went over how to do that.

you need to vac the system, and you need to properly monitor how you recharge it, or you're wasting a bunch of money on new parts that are just going to go bad again because you're not fixing the problem properly.

No disrespect intended, just my .02.

[Atreus21]

Re: How do you change an A/C compressor?

Where is the low side AC line in the 3800?

[Firebirdkid96]

Re: How do you change an A/C compressor?

On the front of the car, by the radiator cap.

The receiver dryer should be your high pressure side.

edit:

reverse that i got mixed up.

[Rob Bell]

Re: How do you change an A/C compressor?

The receiver dryer is the low side. The low side stuff is what gets cold. The part by the radiator is high pressure, don't mess with that.

[Atreus21]

Re: How do you change an A/C compressor?

Well I've seen alot of discussion on this and having replaced now three compressors I feel the need to chime in.

First, evacuating the system.

Yes, before you refill the system it needs to be evacuated. but we're not talking about evacuating it of refrigerant. Odds are if you're replacing your compressor, the shaft seal was leaking the r-134a and so you aren't dealing with it anyway. You evacuate the system AFTER you've installed the new compressor to get any moisture and little debris out of the lines, the receiver-dryer...etc. To do so you'll need an a/c manifold which is a device with two gauges and three lines. One line is your high pressure fitting one is your low pressure. The high pressure side is the side with your receiver-dryer and condenser, the low pressure side has your evaporator. you cant mix them up. the center line is used as an interface for refilling, evacuating, whatever you're putting in or taking out of the system. To evacuate the system, the easiest way is to go to harbor freight tools website and order an "a/c vacpump". you'll also need an air compressor top do this. IT IS VERY IMPORTANT THAT YOU NOT SKIP THIS STEP. YOU NEED TO GET EVERYTHING OUT OF THERE. if not you'll be replacing your compressor again lol. trust me.
here's the link.
http://www.harborfreight.com/cpi/cta...emnumber=96677

and this is the manifold
http://www.harborfreight.com/cpi/cta...emnumber=92649

next thing you need to remember is that before you put the compressor back on, you need to fill it with a/c compressor oil designed for r-134a compressors. you can get this at any auto parts store.

as far as refilling the system, you'll refill it with R-134a, which is not a restricted gas. I believe the sticker on v6's calls for 1.68 lbs of refrigerant, I recommend keeping it at 1.5 because if you overfill (which is easy to do), the pressure will become too high, and blow the seal. you can also fill it with a special dye that shows up under UV light so you can tell if it's ever leaking.i'll do a writeup on this when I replace my compressor in about a week. :tup:

and for the discussion on r-12 and r-134a.... freon is a term copyrighted by the dupont company as a trade for their chlorofluorocarbon and hydrochlorofluorocarbon refrigerents.
R-12, commonly known by it's freon-12 brand name is a restricted gas because of it's reactive nature, and it is a methane with two chlorine atoms and two fluorine atoms, making it highly detrimental to our O-Zone because it is saturated. You need a license to purchase R-12 and it's being phased out of use in automotive applications. Now we use R-134A, also know as Freon 134-a (see how this works lol, its like ppl calling tissues kleenex) because while it is still not safe, it does not deplete the ozone because it is hydrated by the presence of two hydrogen atoms. HOWEVER, R-134a is still dangerous because it is an asphyxiant. dont breathe it in lol.

here's a pic of how the system works.



hope this helps!

You said it calls for 1.67 lbs of refrigerant. How do you know how much you've put in at any given time? The little guage that came with the recharge kit shows PSI, but it's in multiples of ten.

[Rob Bell]

Re: How do you change an A/C compressor?

The gauge I have has different colored zones, too. It's from Interdynamics. It shows 0 - 25psi as green on the low pressure side. I just do mine until it's on the upper side of the green zone (not way up there, though) and the air feels cold. You're not going to know lbs unless you fill it up from totally empty and evacuated, anyway. Just get it so it's nice and cold.