R-12 to R-134A energized system

[dubadaddy]

Guys,

My indie says he cannot put in the R-12 I got him and he put in R-134A instead. He says the '92 300 CE has already been "converted". When pressed I asked him the difference and he said the fittings on the hoses are different for the R-12 to R-134A.

Can I go back to the R-12 so I don't have to get it recharged every year??

What does this do to the seals in the compressor?

He says the hoses need to be changed for it to go back!?

Well there are several issues at play in your post.

To begin with, your comment makes it sound as if you believe that changing back to R12 will prevent you from charging it every year. If you have to charge it every year you have a leak. A leak is a leak, regardless of refrigerant, although some refrigerants can sometimes leak at different rates.

The hose issue. You would not have to change hoses to go back to R12. What you WOULD have to do, is break every connection and flush every component, remove the adapter fittings, replace the r/d put in the correct amount of mineral oil or a synthetic substitute, evacuate and charge with R12.

[dubadaddy]

R/D??? What is that?

I have heard that the R-12 system is the better of the (R-134A).

What kind of cost can expect to incur??

[gmercoleza]

R/D = receiver dryer.

R12 is better in a system which was originally designed for it.

I have no idea what someone would charge to convert - I always did it myself.

[rchase]

Originally Posted by dubadaddy

Guys,

My indie says he cannot put in the R-12 I got him and he put in R-134A instead. He says the '92 300 CE has already been "converted". When pressed I asked him the difference and he said the fittings on the hoses are different for the R-12 to R-134A.

Can I go back to the R-12 so I don't have to get it recharged every year??

What does this do to the seals in the compressor?

He says the hoses need to be changed for it to go back!?

I had my 300SD and Porsche converted to R134 professionally. They both cool just as well as an R12 system. In fact the Porsche with its tiny cockpit and less advanced thermostat gets uncomfortably cold. To agree with others here. A leak is a leak. R12 or R134 your on a slippery slope maintaining the correct pressure in your system if its leaking.

If you don't want to deal with the leak right now stick with the R134 its less harmful to the environment. Good thing EPA inspectors are not frequently Mercedes owners. It would be citations gold around here just trolling the A/C posts.

[Matt L]

Originally Posted by rchase

If you don't want to deal with the leak right now stick with the R134 its less harmful to the environment. Good thing EPA inspectors are not frequently Mercedes owners. It would be citations gold around here just trolling the A/C posts.

Pick a brand and find a forum, and you will see the same thing. I'm sure that the EPA is just not too interested in going after owners. That said, I sure wouldn't advertise that I'm breaking any of their rules, even as silly as some of them are.

[ds190]

Duba, you also know that our 124 cars have an evaporator core that frequently leaks due to a poor design from the factory, and many have to be replaced, right?

So, your mechanic should do a leak test with dye before he recharges it w/ 134 to find out why your system is loosing refrigerant.

[rchase]

Originally Posted by Matt L

Pick a brand and find a forum, and you will see the same thing. I'm sure that the EPA is just not too interested in going after owners. That said, I sure wouldn't advertise that I'm breaking any of their rules, even as silly as some of them are.

Very good point.

If the EPA could monetize going after the owners and generate some revenue in the process I would watch out. They have done the same thing with traffic tickets and red light cam's.

With the cash for clunkers programs and fuel price increases and new fuel economy standards and Detroit unable to sell any of their horrible cars I would not be surprised if they started going after owners like us for minor issues like this just to drive our costs up and perhaps land a few of us in a fabulous plastic hybrid in the process.

[Matt L]

The later Prius cars have ACs that run without the engine. That would be pretty cool. It would be even better if they used an off-the-shelf hermetic scroll compressor.

I found out something bad about my Jetta'a AC system. Because there is no clutch on the AC compressor, you essentially can't drive the car without refrigerant. The service manual says that you can run the engine not exceeding 2000 RPM for up to 10 minutes without refrigerant, but the system must be completely assembled and at least 1/4 of the required oil charge must be in the compressor.

[rchase]

Originally Posted by Matt L

I found out something bad about my Jetta'a AC system. Because there is no clutch on the AC compressor, you essentially can't drive the car without refrigerant. The service manual says that you can run the engine not exceeding 2000 RPM for up to 10 minutes without refrigerant, but the system must be completely assembled and at least 1/4 of the required oil charge must be in the compressor.

That's rather interesting. Perhaps an intentional design flaw to sell high profit A/C compressors. Customer on the expressway looses coolant pressure on a nice day and does not notice and destroys the compressor and can't drive their car without replacing it even if they live in a climate that does not really require A/C.

I wonder what will happen when that car gets 10 years old or so. Many "basic transportation" 10 year old cars don't have working A/C.

[Matt L]

If the compressor locks up, there is a shear coupling that gives way and the pulley rides on a bearing. So it won't leave you stranded unless the shear coupling or pulley fails. However, I've heard of pulley failures on these compressors, when the compressor was not locked up.