A/C Question (for experts, late W126)

[hbofinger]

Hi,

So I am about to replace the dreaded expansion valve on a modified (R134a) system on my 1989 560 SEL (W126). Since the system has been completely empty now for almost a year, and not been run, I wonder about how much oil I should add.

Details:
* replacing Expansion valve
* replacing Receiver/Dehydrador
* evacuating system
* charging up with 134a

I am having a hard time coming up with specs. I think I need 36 oz of 134a, but I don't know the rest.

Interesting thing is that I just read the thread here on the R134a being sold with sealant in it. I'm glad I saw it before I went for it. I also realized at Target that all of the refrigerants sold with oil also have the sealant in it. So I am back down to using nothing but straight 134a, and squirting the oil manually into the system before closing it up.

The CD is confusing, and has contradictory information as follows:

manually check by opening oil port on compressor and fill to overflow
OR
Fresh oil in compressor: 170cc
OR
Add ref. to system above 200g (my case, because it's empty): 30cc
OR
Renew rec/dehyd. 40cc

Nothing about renewing exp. valve

What do I do? Do I just check the compressor oil port, squirt in till overflow, and add 134a without any additional oil in it? Or do I buy premixed 134a with oil in it (sounds dangerous to me now, by the way)? Or add in 70 cc (new refrig. 30cc + new rec/dehy 40cc)?

Thanks for any input!