Another AC coolant conversion thread..

[zaccaglin]

Okay so the compressor in my suburban blew last year. I bought a new one never used and will be installing it this next week. As for the coolant it is an r12 system(duh) and I plan to convert it to 134a just because I don't really want to try and find r12 for a cheap price. I just want cold air before I head to Florida. As for the conversion I know I need to buy a new accumulator/dryer and that's no biggie. As for the Everything else I found a conversion kit at the Walmart I work at, any one use it or one like it before? We also sell the coolant + oil is that the right oil I need? What about coolant after that should I buy the high mileage or just regular 134a? How much coolant will I need for an 85 burb with rear AC?

Anything else I need to buy? I do plan on having a local shop vaccine out the coolant properly.

Thanks for yalls help.
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[zaccaglin]

Conversion kit.
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[zaccaglin]

Coolant + oil
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[lanconcj]

I just had my single cab done. I think it held 2.4 lbs. I bought a new delco comp. and changed the drier and oriface tube. My Texas summers are NICE now. I have read that the 134a will cool better with a 134a specific condenser but mine works great with the old one.

[zaccaglin]

Originally Posted by lanconcj

I just had my single cab done. I think it held 2.4 lbs. I bought a new delco comp. and changed the drier and oriface tube. My Texas summers are NICE now. I have read that the 134a will cool better with a 134a specific condenser but mine works great with the old one.

Is the oriface tube recommended or did you do it simply because you wanted a higher temperature one (being in texas and all). Where is it located on our system?

[rs74]

On other vehicles in the past I have just put the conversion kit fittings on. Didn't replace anything else and they always worked fine once I vac'd it down and put new 134 in it.

[odee]

I would pull the orfice tube and check it out to see if when the compressor went it didn't stop up. I think there is a different one that will give somewhat colder air.

[zaccaglin]

Originally Posted by rs74

On other vehicles in the past I have just put the conversion kit fittings on. Didn't replace anything else and they always worked fine once I vac'd it down and put new 134 in it.

That's what I was planning on. Figured I would replace the dryer too.

Originally Posted by odee

I would pull the orfice tube and check it out to see if when the compressor went it didn't stop up. I think there is a different one that will give somewhat colder air.

Where is it located on our rigs? My compressor froze up when I was going about 90mph one afternoon coming home from pick n pull (the irony..)
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[jon75]

When installing a new compressor, you should pay attention to how much oil is required for the system. R134a systems use PAG oil. It's quite cheap and I recommend taking an extra moment to ensure you have the correct amount in the system.

Prior to installing the compressor, remove any plugs that are sealing up the port holes and dump out all of the oil that was in the compressor out into a container. Check the labels on your truck to see how much oil the system calls for, and add that amount into the compressor ports before installing. Next, install the compressor. Be sure that you replace EVERY SINGLE O-RING with O-rings that are rated for R134a. They are usually green and a kit for that is around $4 at O'Reilly's or NAPA. After you have finished replacing the O-rings, filter/drier, and anything else, install the quick connects for the R134a onto the R12 ports on your system, paying close attention to the difference between high and low side (high side is post compressor, pre-evaporator). Once you have installed the ports, put a vacuum on the system of 30 inches. It should hold the vacuum for 5 minutes without falling below 29 inches. If it does, you have a leak in the system (most leaks will be evident right away and you won't have to wait that long to see the vacuum drop).

Once you have verified that you do not have any leaks, NOW you can charge the system. The system will take the first pound or so very quickly, since it is still under vacuum. Make sure that you use a gentle rocking motion on the can as you are filling the system. Be sure to measure out with different can sizes how much you need to fill the truck with. It is best to go under the allowable amount rather than over. For instance, if you need 2.2 lbs but you can only find 2-16 oz cans, just go with that. You will have nice cold air and your system won't be stressed. DON"T PUT IN TOO MUCH!! After you have gotten most of the refrigerant into the truck, it may not take the last little bit very easily. If this happens, start the car and run it on MAX a/c with all windows up and the driver window down 2 inches. If it does not take the last bit as the vehicle is running, turn the can upside down and gently rock from 10 o'clock to 2 o'clock positions until all the refrigerant is out.

Once you have charged the system, make sure that the compressor clutch is cycling on and off correctly (which should happen immediately after you start charging the system), you don't hear any odd hissing noises from any lines, and that the air inside the truck feels nice and cool.

I hope this helps you out. This is the system I have adopted from working out of my garage fixing A/C systems without the use of a $5000 machine. All I have is an air run vacuum, a/c manifold gauge set, and the refrigerant cans. I have not had one single complaint and I am EPA and ASE certified in A/C and heating systems. Good luck!

[jon75]

Oh, one last thing....don't get the refrigerant with oil or stop leak in it. Just get the regular stuff.

[zaccaglin]

Originally Posted by jon75

Oh, one last thing....don't get the refrigerant with oil or stop leak in it. Just get the regular stuff.

Thanks for the awesome write up. When I add the pag oil do I subtract that amount from the total amount of refrigerant Ill be adding to the system? My current (failed) compressor takes 8.0oz of oil. I'm sure the new one is close to the same amount but ill double check tonight. And my system says it takes. 3.25lbs of refrigerant. After doing the whole r134a will only need 85% of what r12 would use it looks like ill need 44.2oz of refrigerant if I don't subtract the pag oil don that.

Another thing you said to pour the pag oil into the compressor I see what we gave this at my Walmart. Do they make just straight oil that's not in a compressed can like this? I'll check napa tomorrow.
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[zaccaglin]

Called napa. They have pag 100 in the quart size as well as the o ring kits. Will pick them up tomorrow with some refrigerant. Now just to find a shop to do the vaccine for me.
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[Big Port Jimmy 6]

I second the motion to change the orifice tube to one of the variable types. They are usually around 15-20 bucks. They make a difference. Jay

[zaccaglin]

Originally Posted by Big Port Jimmy 6

I second the motion to change the orifice tube to one of the variable types. They are usually around 15-20 bucks. They make a difference. Jay

Where are they located on our rigs? I can't seem to get a clear answer on that one. Also when looking at them on rock auto how do I know which is variable?

Is this like what your talking about? http://www.rockauto.com/catalog/more...807&cc=1300206
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[jon75]

Originally Posted by zaccaglin

Thanks for the awesome write up. When I add the pag oil do I subtract that amount from the total amount of refrigerant Ill be adding to the system? My current (failed) compressor takes 8.0oz of oil. I'm sure the new one is close to the same amount but ill double check tonight. And my system says it takes. 3.25lbs of refrigerant. After doing the whole r134a will only need 85% of what r12 would use it looks like ill need 44.2oz of refrigerant if I don't subtract the pag oil don that.

Another thing you said to pour the pag oil into the compressor I see what we gave this at my Walmart. Do they make just straight oil that's not in a compressed can like this? I'll check napa tomorrow. Attachment 1115097
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If it were me, I would put in all new oil. My local stores have 8oz bottles that are not compressed, just pour bottles that are $9.

As far as the 85% thing, I am not sure where you heard that. If I somehow led you to believe that, I apologize. I didn't mean to. I was simply saying to add as close to the refrigerant amount without going over. If you can get a 44oz can, do that. You should be able to find a 22oz bottle. Just put in two of those and you are set.

Also, you do not subtract the 8oz of oil from the 44oz of refrigerant. If it says 44oz of refrigerant, that is how much you put in.

[zaccaglin]

Originally Posted by jon75

If it were me, I would put in all new oil. My local stores have 8oz bottles that are not compressed, just pour bottles that are $9.

As far as the 85% thing, I am not sure where you heard that. If I somehow led you to believe that, I apologize. I didn't mean to. I was simply saying to add as close to the refrigerant amount without going over. If you can get a 44oz can, do that. You should be able to find a 22oz bottle. Just put in two of those and you are set.

Also, you do not subtract the 8oz of oil from the 44oz of refrigerant. If it says 44oz of refrigerant, that is how much you put in.

The 85% idea is what I've read on all the DIY kits. If its safe at 44oz ill do it.
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[zaccaglin]

Originally Posted by jon75

If it were me, I would put in all new oil. My local stores have 8oz bottles that are not compressed, just pour bottles that are $9.

As far as the 85% thing, I am not sure where you heard that. If I somehow led you to believe that, I apologize. I didn't mean to. I was simply saying to add as close to the refrigerant amount without going over. If you can get a 44oz can, do that. You should be able to find a 22oz bottle. Just put in two of those and you are set.

Also, you do not subtract the 8oz of oil from the 44oz of refrigerant. If it says 44oz of refrigerant, that is how much you put in.

What's your thought on the orifice tube?
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[lanconcj]

Changing the orifice tube was recommended to me. It is located in the tubing. Do a forum search for orifice tube, I know there is a picture on here somewhere.

[zaccaglin]

Originally Posted by lanconcj

Changing the orifice tube was recommended to me. It is located in the tubing. Do a forum search for orifice tube, I know there is a picture on here somewhere.

Yep I found it. Thanks.

http://67-72chevytrucks.com/vboard/s...d.php?t=297111
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[jon75]

It surely won't hurt anything to put an orifice tube in. Sounds like a good idea to me.

I have always tried to charge systems as close to capacity as possible, even the ones that are retrofitted. I actually worked on my instructors 80's Corvette we were retrofitting in college and we filled that to capacity as well.

[zaccaglin]

Originally Posted by jon75

It surely won't hurt anything to put an orifice tube in. Sounds like a good idea to me.

I have always tried to charge systems as close to capacity as possible, even the ones that are retrofitted. I actually worked on my instructors 80's Corvette we were retrofitting in college and we filled that to capacity as well.

Sounds good I ordered a 105+ degree one with my accumulator from rockauto today. Now just to track down all that freon at a good price..
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[chris989]

Originally Posted by zaccaglin

Okay so the compressor in my suburban blew last year. I bought a new one never used and will be installing it this next week. As for the coolant it is an r12 system(duh) and I plan to convert it to 134a just because I don't really want to try and find r12 for a cheap price. I just want cold air before I head to Florida. As for the conversion I know I need to buy a new accumulator/dryer and that's no biggie. As for the Everything else I found a conversion kit at the Walmart I work at, any one use it or one like it before? We also sell the coolant + oil is that the right oil I need? What about coolant after that should I buy the high mileage or just regular 134a? How much coolant will I need for an 85 burb with rear AC?

Anything else I need to buy? I do plan on having a local shop vaccine out the coolant properly.

Thanks for yalls help.
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make sure to flush the system before you install any new parts. I bought my flush can and solvent from Napa. just hook it to your compressor and blow the air/solvent mixture through your condenser and evaporator coils.

it is well worth it to insure there is no old oil or contaminants in the system.

AC System Flush - AutoZone Car Care - YouTube

[zaccaglin]

Originally Posted by chris989

make sure to flush the system before you install any new parts. I bought my flush can and solvent from Napa. just hook it to your compressor and blow the air/solvent mixture through your condenser and evaporator coils.

it is well worth it to insure there is no old oil or contaminants in the system.

AC System Flush - AutoZone Car Care - YouTube

Wont having the system vacuumed out, then installing the new compressor, and the new dryer be enough to clear it out?

Edit:
Just saw you included a video and watched it, i guess ill get some quotes to have a local shop do it for me.

[chris989]

Originally Posted by zaccaglin

Wont having the system vacuumed out, then installing the new compressor, and the new dryer be enough to clear it out?

Edit:
Just saw you included a video and watched it, i guess ill get some quotes to have a local shop do it for me.

i bought the flush can from napa. maybe 80$ if you have a compressor it is easy to do and not a bad tool to have in the future.

[Desert1957]

Originally Posted by zaccaglin

Wont having the system vacuumed out, then installing the new compressor, and the new dryer be enough to clear it out?

No it will not vacuum any "Junk" out.

After any component failure you have to flush out each component separately, which means breaking open all connections flushing all the parts individually (condenser,evaporator, and all lines). Blow remainder of flush solvent out, let system dry. Install NEW orifice tube, add proper amount of new style pag oil. Reassemble system, install accumulator or drier LAST (accumulator as a desiccant that starts absorbing moisture)

If you did have a "Compressor Failure" it was coming apart pumping crap all through the system before it went out completely.

During this conversion you MUST change ALL the o rings to 134 A compatible style. If not they will leak.

These are the reason for pumping your system down after it has been opened up,

*completely eliminates any air from the system
*any remaining moisture will boil into vapor and be eliminated during the process
*will partially tell you if you have any leaks,
(should hold between 28" and 30" of vacuum)

If you just replace the compressor and orifice tube , without doing the steps above it will fail again.

After you get your $1000. estimate we can walk you through doing your repair yourself for 1/2 the money.


Desert