[crockett07]

i took my xj to the shop this morning to see what it would take to get the AC fixed. they told me they couldnt do anything untill it was retrofited which would cost me $200 with no gaurantee of it blowing cold air. i know a few guys at the shop and they told me to get the retrofit parts kit and do it my self then bring i back up to put the refrigerant in and take it from there. i bought the retrofit parts kit and the valve removal tool and so far im only 20 dollars in. i popped the hood and im lost. i can do anything to my jeep but i dont know anything about ac systems. can anyone tell where and how to put these fittings on?

[Reptile]

You invested 20 bucks in a ticket for black death. There is a lot more you'll have to do than just installing fittings. The oil in R12 systems poses critical compatibility issues with replacement refrigerant. You'll have to flush the entire system, refill with ester or PAG oil and recharge to specs. Or find some good old R12.

[crockett07]

thats fine and well. as of right now i am trying to retrofit the fittings so further steps can be made. i need help knowing how these fittings go on and where...

[AZ Jeff]

Originally Posted by Reptile

You invested 20 bucks in a ticket for black death. There is a lot more you'll have to do than just installing fittings. The oil in R12 systems poses critical compatibility issues with replacement refrigerant. You'll have to flush the entire system, refill with ester or PAG oil and recharge to specs. Or find some good old R12.

Its OK to leave the R12 oil in the system, PROVIDED he replaces the receiver/dryer, where most of the oil sits when not operating.

Here is what the OP needs, in general, to convert from R12 to R134a:
1. Remove all R12 from the system via evacuation (the shop will do this)
2. Replace all o-rings on any joints in the system with R134a compatible types (this means disconnecting any threaded or slip fit connections and swapping the o-rings. Cost—about $20 if you do it yourself and buy the slip fit disconnection tool)
3. Flush the system with a refrigerant flushing agent and compressed air. (you can do this yourself while the system is apart)
4. Replace the receiver-dryer. (you can do this as part of step 2 above, with a total cost of probably under $50)
5. Install teh correct R134a type fittings on the old R12 charging ports. (You can do this yourself as part of step 2)
6. Install the correct amount and type of R134a refrigerant oil (The shop will do this)
7. Charge the system with the appropriate amount of R134a refrigerant.
If you do steps 2, throught 5, and pay the shop to do steps 1, 6, and 7, you should wind up with the best chance of a working system for the lowest cost.

[AZ Jeff]

Originally Posted by crockett07

thats fine and well. as of right now i am trying to retrofit the fittings so further steps can be made. i need help knowing how these fittings go on and where...

Do you know how to identify the charging ports for an R12 system? They are on the refrigerant lines and have some small threaded plastic caps to protect against crud getting into the schrader valves (liike on a tire stem)

[rssuby2001]

The small line is the high side, dont charge through this line, all u have to do is have the r12 taken out, put in a new drier, and charge it once a year, the new "o" rings arent needed unless u have a leak

[crockett07]

I think I have found the two charging ports on the back side of the compressor. Both small one, one bigger than the other. Look like tire stems? Neither of these have valves in them and this is why I'm getting confused

[crockett07]

These?

[Reptile]

Originally Posted by crockett07

These?

Yes. The low side is on top; that's the one you want to hit.

Originally Posted by crockett07

I think I have found the two charging ports on the back side of the compressor. Both small one, one bigger than the other. Look like tire stems? Neither of these have valves in them and this is why I'm getting confused

They don't have stems, they are valve operated; that's the point of installing those fittings. The valve work backwards (clockwise to open); don't open them all the way though.

Originally Posted by AZ Jeff

Its OK to leave the R12 oil in the system, PROVIDED he replaces the receiver/dryer, where most of the oil sits when not operating.

Here is what the OP needs, in general, to convert from R12 to R134a:
1. Remove all R12 from the system via evacuation (the shop will do this)
2. Replace all o-rings on any joints in the system with R134a compatible types (this means disconnecting any threaded or slip fit connections and swapping the o-rings. Cost—about $20 if you do it yourself and buy the slip fit disconnection tool)
3. Flush the system with a refrigerant flushing agent and compressed air. (you can do this yourself while the system is apart)
4. Replace the receiver-dryer. (you can do this as part of step 2 above, with a total cost of probably under $50)
5. Install teh correct R134a type fittings on the old R12 charging ports. (You can do this yourself as part of step 2)
6. Install the correct amount and type of R134a refrigerant oil (The shop will do this)
7. Charge the system with the appropriate amount of R134a refrigerant.
If you do steps 2, throught 5, and pay the shop to do steps 1, 6, and 7, you should wind up with the best chance of a working system for the lowest cost.

I'd definitely do the O-rings. They're the most common cause for leaks, especially if they're 20+ yrs old. Use HNBR rings only. You're supposed to evacuate the system through a recovery system by law... but if it's blowing cold you probably don't have much refrigerant left if any. It is recommended to replace the dryer; if you don't your AC won't be as cold, but still work.

[AZ Jeff]

Originally Posted by rssuby2001

The small line is the high side, dont charge through this line, all u have to do is have the r12 taken out, put in a new drier, and charge it once a year, the new "o" rings arent needed unless u have a leak

Where did you get your experience on AC systems? The rubber o-rings on an R12 system are not comaptible with R134a and it's oil, and if they are not already hard, dry, and leaking, they will be once the R134a is in the system.

[Motorcharge]

You can always buy r12 connections and get a couple cans of Freeze 12 and put it in the existing system as well. It's just as cold as 134 and cheaper than taking it to someone to service it.

You might call around too, I didn't think I could get r12 around here anymore but I found a local company that still had some and would fill mine provided I brought them proof from a dealer that my system didn't have any leaks in it. It's more expensive, but it blows a hell of a lot colder than 134 does.

[crockett07]

all this information is great guys thanks. how do you open the valves? the reason im asking this is because i believe they're already wide open. i can stick a small drill bit in there almost half way into the block they're connected to.

[Reptile]

Originally Posted by Motorcharge

You can always buy r12 connections and get a couple cans of Freeze 12 and put it in the existing system as well. It's just as cold as 134 and cheaper than taking it to someone to service it.

You might call around too, I didn't think I could get r12 around here anymore but I found a local company that still had some and would fill mine provided I brought them proof from a dealer that my system didn't have any leaks in it. It's more expensive, but it blows a hell of a lot colder than 134 does.

Freeze 12 is nothing more than a blend refrigerant that mainly contains R134a. Beware of those. Do your research and find out about long term success vs failure rates... If you go that route, you might as well consider propane based refrigerants, which have far more potent refrigerant properties and true drop in refrigerants... but are obviously flammable. Keep in mind that each refrigerant has its own charge specs.

You can find R12 on ebay but you're gona pay through the nose. Compared to the cost of conversion is still cheaper, as long as you don't have major leaks. I would still replace the rings if you're going to spend 60-100 bucks on refrigerant.

Originally Posted by crockett07

all this information is great guys thanks. how do you open the valves? the reason im asking this is because i believe they're already wide open. i can stick a small drill bit in there almost half way into the block they're connected to.

Remove the caps and use a wrench with 8 point socket (1/4in I think).

[crockett07]

Originally Posted by Reptile

Remove the caps and use a wrench with 8 point socket (1/4in I think).

is that just a regular 1/4" sockett? how does that work?

[Reptile]

Originally Posted by crockett07

is that just a regular 1/4" sockett? how does that work?

Regular sockets are 6 pt, they look like an hexagon. The valve has 4 sides so you need a socket that has a multiple of x 4 pt. 12pt would technically work, so is a combination wrench but they won't grip as well and might mess it up. 8 pt sockets work very neatly for this application.