I am in the process of fixing a leak in my already converted to R134a A/C system on a 1987 300D (Done before I bought it). I have flushed out the system, changed the dryer, and now I am adding oil.

I have a bottle of PAG 46 - Thin Oil as per my Denso compressor. Do I pour the 8oz. recommended all into the back of the compressor and turn it about 10 times or do I split half into compressor and the other half into the dryer?

Or do I add oil using one of those 10.5 oz cans of R134a that has 8.5 oz of PAG oil in it (O-Ring Conditioner) and send it through the low pressure port? What is the difference with this type of oil?

The sticker on the vehicle states that for the old R12 system to put in 1.1kg or 2.4lbs of R12 recharge. But since the pressures are different in the two system:
*DOES ANYONE HAVE THE FORMULA FOR THE AMOUNT TO PUT IN?
*Do you need to subtract the 8oz of oil from this amount?

I'd add the 8 oz, split between compressor and R/D; then turn the compressor like you stated. I'd avoid "seal conditioner"; it sounds like you've "done it right", so skip the Interdynamics Inc. additives.

Pull a deep vacuum; really deep with PAG, to insure the moisture is out.

I prefer POE type oil (the new stuff) on a conversion, but others disagree......

Charge into the vacuum with ~80% of the R12 charge (I'll let you compute); then keep adding an once or two at a time; monitoring vent temp and hi and low pressures with gauges.

At ~85% of R12 weight, you should be really close to done.

The oil is in addition to the weight of refrigerant.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

What is involved in pulling a "deep vaccum"?

After the oil is in, do I let in 80% of R134a into the low port and then start the A/C followed by checking the pressures of high and low?

What pressure readings am I looking for?

Thanks.