Has anyone had any luck, converting the ac system from R-12 to the new 134 system? I've never been real happy with the functioning of my 240's a-c. I replaced the compresor and drier, and was told everything else checked out fine.

I live in the hot inland area of So. Calif, and I was able to make my wife's '87 240 A/C work great.
I purchased the r134 volvo conversion kit from Beechmont Volvo in ohio. Ask for the volvo club discount, came to $140 with no tax and free shipping.
This kit comes with a new evaporator, high side hose, an expansion valve designed for r134,new drier, and o-rings.

I then purchased the standard R12 expansion valve, plus all of the other hoses in the new barrier style material from GAPA parts online. Replacing the evaporator is really not that hard and Beechmont volvo sent along a complete copy of the service instructions for the kit to make things easier. I found that the original evaporator had lots of dirt caked on the outside fins from the incoming air. This is why the air flow had diminished over the years.

After replacing all the parts, I then evacuated the system and charged with the proper amount of R12, The system absolutely works great, and the annual loss of freon through the old hoses is gone. It's been over a year now and still no bubbles in the sight glass!

Why recharge a system that was designed as marginal with R134 that is even less efficient at cooling. R12 is available at all A/C shops if you want them to charge the system. If not, get your A/C license online for $20 bucks and then purchase the cans of R12 at Autozone for $15 per can.

The cooling of the A/C even in 110 deg weather is very good, and the evaporator is so efficient that pools of clear water form under the car from the drain hose.

Total cost $275 and one day of work.

In case this might encourage you to do you own upgrade: The PO of my 242 spent $1265 to have the entire system replaced for the new type of refrigerant. This is on the 81 I've been working on for four months to fix all kinds of other problems. Expensive proposition.
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Thanks to everyone for the help, Doug C. 81 242 Brick Off Blocks, stock; 86 240, 129K

i replaced all my stuff about 2 years ago and always got about 34-36 degrees out the vents. ONLY replace the 134a at 80% the volume than with R-12. your existing system WILL NOT handle the added pressure. get under the dash on the passenger side and unwrap the T connctor that has the copper wire going to it. replace it as well. sorry but i've forgotten the name. when you disconnect, only allow as little air in the lines as you can. tape the opening off. do yourself the biggest favor you can and get a pusher fan from a wrecked 740 or sometimes a 240 turbo. you can find those all day long at u-pull yards for small $$'s. mount it on the front of the radiator where it will push air through using the esisting holes (i moved my hornes down to get another hole in the center.) also, see if you can't get a copy of rolling from last year that shows you how to seperate the two radiators for more air flow. make sure you can put 3lbs of vacuum on your system or it won't be worth all of this trouble. it will take a while for the 134a to load but take your time. after you've filled the system. re-tighten EVERYTHING. get your garden hose out and spray cold water through the radiator while the system is running for about 5 - 10 minutes. viola', cold air. another BIG help is to make the investment of tinting your windows. the factory tint acts like a solar panel in the summer.

good luck.....
bubba
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what...???...me worry??

When you guys are talking about blowing mid-30s from the vents, how are you measuring this? By sticking a true digital thermometer in the vents? If so, what's the temp outside when you measured it? Reason why I'm asking is that I'm having my A/C converted over in about 2 weeks. I live in FL where it's in the 80s now and I find it hard to believe that I'll be pumping out 30s-40s from the A/C vents in this humid/hot weather. Perhaps I'm missing something?
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Regards,
Eric Staufer,
'89 244DL 118k
My 240 Page

Bubba's advice is 110% true. The vacuum makes all the difference.

Additionally, if you can, add a condenser cooling fan. You can get them on the aftermarket for seventy bucks or less, and put in a relay to run it when the compressor is running. What it does, is it keeps the system from getting 'backed up' with too much heat that it can't transfer out.

Many 240s I've worked on have had very cool conversions. Tinted windows make a huge difference. And a tan dashmat if your car has a tan interior. It keeps the huge black dashboard from attracting too much extra heat.

Sitting at idle in traffic, temps in the thirties are not practical. If you get a 40 degree drop from ambient, it's a pretty good conversion. Although you can get even more than that if the sun isn't beating into the car and making the system draw more heat out of the interior.

On a 240 sedan, the chances of a good conversion are very good. The wagons, with the big warehouse to keep cool, are a little bit more of a challenge. But still possible.
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chris herbst, near chicago

the key is pretty much everything i mentioned in my previous post. the most important is to get a 3lb vacuum on your system or don't waste your time or money. you should be able to rent one or at the least, you can buy one from jcwhitney for about 25$$. the other key, key thing is to ONLY put in 80% volume of the 134a than what is required for r12.

i live in atlanta and we have close to the same temp. now don't expect that as soon as you jump in that it's gonna get that cool from the start. you'll turn the knob all the way around and drive for about 15 - 20 minutes then turn it down to the normal position.

my temp were measured by an industrial dial temp guage.

good luck.


Bubba
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what...???...me worry??

You can go farther than that; replacing the evaporator (recommended) and putting in a condenser cooling fan will help a lot as well.
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chris herbst, near chicago

Chris:
Is there a "special" evaporator for r134 that is different than the type for r12? Is there a different style of expansion valve for r134 and r12? I have an 86 240 which I converted over. It hasn't really improved my cooling, although it isn't any worse than it has been. But I didn't replace the evaporator, only the receiver/dryer and the expansion valve.

Thanks for the help.

Mike Brown
Greenville, NC
1986 244 132K
1996 965 93K

The expansion valve is important. There is an evaporator designed for R134a, which is part of the $200 or so Volvo kit that is part of the recommended conversion.
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chris herbst, near chicago

Some one else posted awhile back about using "Freeze 12". I ordered their conversion kit for $39.99 It comes with adapters for the low and high side of the compressor, 3, 6oz cans of "Freeze 12" and the hose and valve to recharge. I think it is a hydrocarbon based referigant. It is EPA approved and takes 1/3 the amount of R12 to charge. Supposedly, because the system will be under less pressure you compressor will last much longer. The supplier says this product is much more efficient than R12 and I should be blowing in the low 30's. Anyways I will do the change over when it arrives next week and let all know how it turns out. Heres the link if you are interested.

http://autorefrigerants.com/co00030.htm

sdol,

I am looking to do the same thing, but have not ordered the conversion kit. Where did you order it from? Let me know how it went if you don't mind. Contact me at lhoward@comcast.net

thanks,

Luke

Freeze 12 is:

80% R134a (1,1,1,2-Tetrafluroethane)

and

20% R142b (1,1-Difluro-1-chloroethane)

According to the US EPA's information.
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chris herbst, near chicago