A/C from R12 to R134?

[bp9129]

Just find R12.

It's not that hard to find... and it's 20x colder

[CorvallisBMW]

Freeze 12 is your friend. It uses the R12 system, legal, and cheap.

This would be my recommendation, short of real r12

IIRC, you also need to check and make sure your ac compressor is capable of using the R134 too.

Please correct me if I'm wrong, but certain compressor (newer model e30) can handle both R12 and R134 and some can't. I think there's a thread about it somewhere in the forum. I'm pretty sure if you search, you'll find your answer.

Correct. Late model compressors are 2-way compatible, earlier compressors are not.

Oh, and if you have access and experience to an A/C machine, I recommend pulling vacuum for 30 minutes, inject oil (1 or 2 oz should do), then charge up a little over 2 lbs of R134 and you should be good to go.

The oils used in R12 and R134a will react and eat away rubber seals if they mix together, which is why you should always have a system evacuated to vacuum before changing refrigerants.

The biggest problem is that the compressor is undersized for use with R134a.

Correct.

(Just find R12) It's not that hard to find... and it's 20x colder

You have to have a licence to buy it. Anyone selling it is required by law to check your licence. You can buy it on eBay all day long but not without the proper licencing, so unless you can find some at a garage sale from someone who doesn't give two shits, it's harder to find than you think.

Here is the BMW factory service manual for converting e30s to r134a:

https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B4vP9afE06OqNWI3M2FkMTQtZDczMS00NWVjLWFhNmYtNDc4NGIwZTdkNjdh&hl=en&authkey=CNO6w-8O

[Cong405]

Here is the BMW factory service manual for converting e30s to r134a:
https://docs.google.com/viewer?a=v&p...thkey=CNO6w-8O

This should be stickied somewhere

[bp9129]

Fuck the law. If oyu know people its not very difficult. Craigslist is your friend... I bought a few cans from some old guy last summer. Its easier to just look than doing a whole conversion

[Ryann]

The oils used in R12 and R134a will react and eat away rubber seals if they mix together, which is why you should always have a system evacuated to vacuum before changing refrigerants.

Evacuation does not remove compressor oil from the system. You can pay for an r11 system flush to remove debris and oil, but $$$...

This is why I recommended an r12 drop in vs. a full conversion.

[mutty]

They are not listening Ryann. 100% drop-in. No oil change or change of seals. And the only way to get all the oil out of the compressis to drain then flush. Pretty expensive and time consuming.

[Ryann]

^The only drawback with 414b vs. r12 is that it doesn't perform as well (much like 134a).