R12 conversion

[AdamF 88iS]

Spaz's list is a good summary, but I'll add a couple of E30 specific items:

-Replace the expansion valve. They ALWAYS clog. Don't try to clean it, just chage it because chances are it has a slow leak anyway; too slow of a leak to detect with the vaccuum. The brass fitting on the side comes loose beacue it shrinks/expands at a different rate than the aluminum it's screwed into and eventually won't hold anymore. The design of the valves has been updated so they dont leak anymore when you get a new one.

- There is a small screen/filter in the intake fitting of the compressor. This will probably be clogged. Clean it.

-This isn't required, but I STRONGLY recomend that you change the evap core in the dash. The originals have copper piping that is soldered to the aluminum core. It has the same problem as the brass fitting in the expansion valve; different expansion rates cause them to become a problem. New ones are all aluminum, and as an extra bonus, they ususally come with a new expansion valve attatched anyway.

[Digitalwave]

I'm not going to do any of this myself, I am going to bring it into a shop.

[nickmp0wer]

om bma it looks like the seal kit is 42 and the reciever drier is 50

[AdamF 88iS]

I'm not going to do any of this myself, I am going to bring it into a shop.

You must have deep pockets. Install the componants yourself and just take it to a shop to get the vaccuum and recharge done. The expansion valve and all that is easy.

[jht3]

PERFECT thread! i charged my r12 system in april at my buddies shop. it was blowing COLD at the time but it all leaked out from somewhere as he forgot to add the dye. and the shop has gotten rid of their r12 machine. i sweated my ass off this past summer and don't want to do it again. as much as i'd like to keep the r12 system, i think it's time to changeover to r134a. i want to do this ONCE and do it right.

parts:
evaporator
expansion valve
receiver/dryer
o-rings
charge ports

what's the best way to clean out all the pipes, compressor, and condenser? is it even necessary?
in order to convert to r134a fittings, does the line need to be changed or is it a simple matter of unscrewing the fittings?
anyone know where all the o-rings are? what sizes?

[Digitalwave]

You must have deep pockets. Install the componants yourself and just take it to a shop to get the vaccuum and recharge done. The expansion valve and all that is easy.

So if I were the order the parts from BMA, I'd need the drier, the seal kit, and the expansion valve? How much is an evaporator core and how hard is that to replace?

The process then would be to bring it into a shop that will pay me to evacuate my left over freon, bring my car back and install all the parts, then bring it back to the shop and have it leak tested and filled?

[AdamF 88iS]

So if I were the order the parts from BMA, I'd need the drier, the seal kit, and the expansion valve? How much is an evaporator core and how hard is that to replace?

The process then would be to bring it into a shop that will pay me to evacuate my left over freon, bring my car back and install all the parts, then bring it back to the shop and have it leak tested and filled?

The evap core slides right out after you have the expansion valve out.

You wouldnt need to go to a shop to get it evac'ed first, it's probably already empty.

[Digitalwave]

Alright, in my cart at BMA I have the receiver/drier ($51), expansion valve ($17), and the R134a Retrofit kit ($42) which I assume is all the new seals. Is this all I need (besides the evap core). Where exactly are the seals I am to replace anyways?

That total is $105. The addition of the evap core over doubles that price so I am going to leave that out for now.

How much am I looking at to have the system leak tested and filled (ball park)?

Do I have to worry about moisture or anything when I open up the system, or is that why they spent so much time evacuating the system before they fill it?

[jht3]

Do I have to worry about moisture or anything when I open up the system, or is that why they spent so much time evacuating the system before they fill it?

moisture will enter your system after you open it up. no way around it. evacuating beforehand is just to collect any r12 as it is expensive and also toxic.

once you open it up and get all the conversion pieces put together right, you need to have a vacuum pulled for ~45mins to get every last bit of moisture out of your system. only then can the charge be added.

what part #'s are you looking at buying?

[Digitalwave]

I am unsure of the BMW part numbers, but these are BMA Part's part numbers:

VOL049977 retrofit kit
BMW021728 receiver/drier
MBZ048367 expansion valve

[Digitalwave]

Can someone confirm that that list is all I need?