Do I need to change AC compressor for R-134A?

[Kommando]

Thanks again, just read your post again and missed the pressure switch.

The BMW bulletin and the write up I read forgot to mention the drier and switch. They basically say to evacuate the system, install kit, and fill with r-134a.

[warmsquash1]

No problem. Hope all turns out well and you turn the dash into an ice cube machine. These cars cool veeeeeery well if done right and it sounds like you're on your way!

[Kommando]

I got access to an AC machine and was planning on doing it the proper way, the kit I was looking at is from BMW with all the new fittings and O-rings. I have not looked at the drier yet, but will look into that.

-Thanks

[warmsquash1]

Like anything, there's a right way, a wrong way, and a half-assed way. The wrong way is just topping off the oil and charging it with R134a (unless its already retrofitted which apparently isn't the case here). The right way is to completely flush the entire system, change the pressure switch, the dryer, and the compressor (if yours isn't compatible), sucking the system down to the correct inches of vacuum, put the correct amount of oil (PAG oil or esther oil usually) into the system, shoot some of the correct dye into the system (makes it easier to trouble shoot leaks later, just use a black light), and finally charging the system with the correct amount of R134a using a correct manifold assembly or A/C machine. The half assed way to do it (which I don't suggest or condone, but I've seen it time and time again) is to flush the system, change the dryer and switch, put the oil, dye and R134a in and call it a day. This way may last a couple of days or it may last years. Depends on the compressor. My thought is that if you're going to be in there anyways.... R12 and R134a run on different temperatures and pressures. There's completely different properties between the gases, so it's literally a completely different system. The store bought retrofit kits are only good for being able to utilize the factory lines with the different connectors that are necessary. They should be treated as a COMPONENT WITHIN a retrofit system, NOT an entire retrofit system. Just do us all a favor and don't use Propane... Believe it or not, I've seen it a few times and it scared the SHIT out of me when my machine started yelling four letter words....

[Kommando]

I have been doing some research into this and have hit a wall. I have found lists of compressor part numbers that cannot be converted and ones to use if you have one of those. However the Bosch compressor I have installed is: 0 140 903 208 which I searched online and found this part number: 64 52 1 373 355. I don't see it on the list of non-compatibles, but want to be sure.

What I would like to know is if I can just use the retrofit kit and make sure there is enough oil in the compressor, or if I need to get: 64 52 8 363 550 or another conversionable one?

-Thanks