What is in a RETROFIT kit for 134a?

[Milemaker13]

Just wondering what is included with these "retrofit " kits sold at the auto stores. R12 to 134a. Some of the bottles say they are compatable with R12 and the oils. Can I just add 134a, or do I need a retrofit kit? Does it have new parts?

[azsubaru]

I bought one from NAPA, Item #TEM409998, for about $50.00.

 

It had ester oil, various sized seals, new 134A style valves, and a sticker to let everyone know it's been converted to 134A.

 

I had to replace the compressor, don't know if you really need this if your current compressor is ok.

[Milemaker13]

How well did that work for you? Did you vaccume the system? I was reading that it may be ok to add that kit w/o doing much else. I have even been told it would be ok to just add some 134a, nothing else. I think I want to add some ester oil and 134a and see if it works. If not, probably have a buddy vac the system after I flush it as I have read to do.

[PonchoCatalina]

The best way to retrofit is as follows:

 

1. Have any existing refrigerant reclaimed (some places will do it for free, especially if there is R12 in the system).

 

2. Remove the compressor and drain it of all oil.

 

3. Open all fitting connections and flush the system with a flushing agent (I use mineral spirits and have no problems, but holy wars have been fought over what's best for this). I use a flushing gun that can be filled with flushing agent and pressurized from an from air compressor. Flush your lines, condenser, and evaporator. Do not flush through the expansion valve, dryer, or the compressor! After flushing, dry with compressed air REALLY WELL - a little overkill never hurts here. I usually blow air in one end of a line and cover the other end to build pressure, then release the pressure quickly - it really helps clear the flushing agent out (sort of a "popping" action).

 

4. Replace all o-rings with the correct (R134 compatible) o-rings and smear 'em up with Nylog. Close up all connections.

 

5. Replace the dryer - the dessicant in the old one is probably soggy from being open. Also, I recommend a new expansion valve.

 

6. Fill the compressor with the specified amount of R134-compatible oil. Ester oil is best as it is also R12 compatible if there are any stray contaminants left. Install compressor and seal up its connections.

 

7. Rent (borrow) a vacuum pump from Autozone. Make sure you have vacuum pump oil (available at NAPA) since the Autozone pump will almost undoubtedly be dry. Pull a vacuum and make sure it holds overnight. Don't try to use a $10 Harbor Freight venturi pump - they're just not up to the task.

 

8. If vacuum holds, you should be leak free. You're oil is already in the compressor, so jumper the low-pressure switch, turn on the A/C to Max and add the recommended amount of refrigerant (about 80% of the specified R12 charge).

 

9. Enjoy a chilly cabin this summer!

 

*Note: I have never done an R134 conversion on a Subaru, but some vehicles don't cool as well with R134 as they did with R12. You can increase the efficiency and get cooler vent temps by using a parallel flow condenser, but that's a story for another time.

 

Also, to access a lot more knowledge than I could ever hope to possess, check out the forum at ackits.com. They also sell everything you need to pull this off (and no, I own no stock and am in no way affiliated - I just got a lot of help over there when I got started on automotive refrigeration).

 

Good luck!

- Ian

[Scott F]

Thanks Ian! I want to fix my A/C now in the off season so I am ready for summer. :cool:

 

How much would it cost to have this work done at a shop?

[aba4430]

Scott,

I used either this kit:

http://www.id-usa.com/product.asp?CID=28&PID=218

or this one, I am not sure:

http://www.id-usa.com/product.asp?CID=28&PID=72

I bought it at Advance Auto for ~$30. All I did was rent a vacuum pump and manifold set, and evacuated my system. First time, I did not know how to use the system and did not verify that it held vacuum. As a result I did not note a ruptured A/C hose. So I wasted the first charge. It leaked out after a couple of days. I found the culprit damage on the hose, fixed it with a brass coupling from Home Depot, using two hose clamps. Then rented the vacuum pump and manifold set again. Cost me 20 bucks for a total of 40 for two times. Since I already had the guage and charging hose from the first kit, I just bought 3 X 12 oz. cans of 134A refrigerant with ~3 oz ester oil from Wal-Mart and recharged the system. It has been ~2 years and all is well. Total cost if all would have gone well the first time would have been ~$55.

The detailed way to do it is like Poncho writes above, but I followed the ID recommended procedure and it has held up very well.

aba4430

[PonchoCatalina]

Thanks Ian! I want to fix my A/C now in the off season so I am ready for summer. :cool:

 

How much would it cost to have this work done at a shop?

 

 

To get the full treatment it would probably be fairly expensive. A local shop with a reputation for honesty (in Bryan, Texas) quoted me about $1000, but that included a $300-400 compressor replacement on an '86 diesel Suburban. I was able to buy a NOS compressor off eBay for $18, and I did it myself for a couple-or-three hundred bucks including R12 refrigerant @ $22/can (I'm licensed), the flushing gun, new orifice tube, mineral spirits for flushing, ester oil, o-rings, compressor seals, etc.

 

That said, I think aba4430 has a very reasonable approach, and there isn't really anything to be lost by following his recommendation. It sounds like he has had good luck with the kit, so for a Soob it might be the best (and certainly cheapest) route. I was dealing with dual-air system that had to cool a huge volume in a dark-colored vehicle in Texas in the summer, so R134 wasn't going to cut it anyway. Since I was dealing with 5.25 POUNDS of rather expensive R12, I didn't want to take any chances! Try the kit first and if it doesn't work for you, you can always follow the more exhaustive approach I outlined.

 

P.S. - Borrow a vacuum pump from Autozone - it's free! Just pay a deposit and get it back in full when you return the pump.

[azsubaru]

How well did that work for you? Did you vaccume the system? I was reading that it may be ok to add that kit w/o doing much else. I have even been told it would be ok to just add some 134a, nothing else. I think I want to add some ester oil and 134a and see if it works. If not, probably have a buddy vac the system after I flush it as I have read to do.

 

I think Poncho has a pretty well laid out plan. The kit worked fine for me, at least so far - won't really know until I go through a summer here in Phoenix.

 

I bought a rebuilt compressor off ebay plus a low side hose from a board member, then added oil to the ocmpressor and installed new o rings. Then took it to a shop so they could vacuum, and charge it. They charged me 95 bucks for it. The whole thing cost about $275-$300 bucks, the compressor was about a hundred of that.