I'm replacing the AC compressor on a '89 745T. It already has the 134A retrofit. I'm using a r134a kiki compressor from FCPgroton. The system has the low pressure blue valve cover, I can't seem to locate the high pressure valve, does it have the same fitting type? I have read about a combined valve, but then how to you measure if you have proper(low) pressure?

The system was just evacuated by a shop.

Now I need to replace the compressor. What else should I be replacing/looking for?

Do I need to flush the system? If so, how and where do I flush it from? I will most likely check the oil coming from the old compressor for metal/contaminates.

Do I need to replace any compression seals? Are they standard sizes?

What about the orifice? Where is this located anyways?

Can I do the recharging myself? Or is it best that I have the shop do it?

What about the oil levels in the drier? Do this go bad or should be replaced along with the compressor?

I haven't fiddled with A/C systems before, but have a fundamental understanding of them. I want to tackle this project in preparation for installing an A/C system in my '69 bmw 2002.

I really appreciate replies on this, as I have not found a good source for information in troubleshooting/repair steps for a replacing a 134a compressor. Most of it is on retrofitting.

-Mark