Did they flush the old oil out? If not and then they put 8 ozs in it probably does have too much oil in. 8 ozs is what most people put in after a complete flush of the system. Some even put less in.

Yes, they flushed out all the old oil. Took it back to the shop this morning when the ambient was 79 degrees. The low side showed 42 psi. The mechanic said I can't expect the A/C to perform well until I complete the system and get the A/C temp switch in so that the aux fan will kick in with the higher temps we have been having. I finally got the A/C temperature switch ($58 wholesale, no tax at the dealer) so we'll see if it operates better as it has been unusually hot. Today it suppose to be 95 here in CT today. Envirosafe called me back this morning. The 3rd tech tells me that the R4 compressor should get 4 oz. of oil after flushing. WTH? He also suggest that I switch to the industrial strength ES (which is charged with vacuum) because the 300D needs all the help it can get. My indy charged the regular ES with 0 vacuum. I'm going to give it a few days of running and reevaluate.

I tried to upload the document, guess its to large HERE is the link.

Looks like it is overfilled.

No temp switch= no aux fan. aux fan is needed to remove heat from the system. Why did you bring them incomplete parts and have them start the job?

A temp switch should not cost more than $15 online.

I didn't, the temp switch broke off when he tried to remove it from the old dryer. As it was late Friday afternoon and MB dealer didn't have in stock so had to order it. Try telling your wife to wait a few more days for web delivery when it's 95 and humid out! Especially after we sold her 97 E420 which had ice cold A/C with 198K miles. Peace is sometimes costly...

Your link says:

GM R4: Drain and measure oil. Replace with the same amount of new oil + 1 oz. (3 oz. maximum). Add 1 oz. for drier.

From Yak's DIY Compressorworks R4 writeup: "The FSM section 83-520 has specific quantities to add depending on what you’re doing and how much oil you’ve removed. The compressor re-install section, 83-522, says a total capacity of 170 cc, or 5.75 ounces."

So I gather the recommended range is 4- 5.75 oz. which puts me at 2 1/4- 4 oz. (shop added 8 oz.) too much oil less what spilled when he put the compressor in. When I attach the manifold to the high pressure valve, oil does squirt out. I may have to squirt some oil out to get the pressure down and recharge one 6 oz. can. You can search forever and not find any definitive answer to the oil capacity for the R4 compressor, thanks.

the reason you cannot find the R4 capacity of oil is there is no capacity... just flow of oil through it.
there is no sump.
the R4 changeout on a new compressor takes between 2 and 5 oz of oil.
on a flushed system and a new compressor and dryer, 8oz is ok, but it must be distributed through the system somewhat. most will go in the dryer, and the condenser. only a little goes in the compressor, as it will spill out when you install it in an MB...
if your system was operating fine, and the compressor is all that was removed, and the shop put in 8 oz of oil... you need to pull the compressor, and the dryer, flush out the evaporator, and the condenser and the lines, and recharge with 6 oz of oil in the new dryer, and condenser, then recharge with your refrigerant...
I cannot fathom charging a system with atmosphere in the lines...

The compressor seized 2 or so years ago. We didn't fixed because we had the ice cold A/C in the 97 E420. The shop flushed out the system, replaced the drier, expansion valve and compressor and added 8oz. of PAG oil. He charged at 0 vacuum as per Envirosafe's instructions. I replaced the A/C temp switch and the aux fan is working. I may just recharge under vacuum. As it is, it's like not having A/C after spending $400 labor + $260 for parts. The only question is getting the oil from 8 oz to 4-6 oz....and it's freakin' hot out.

no need to worry about the oil, 8 oz on a flushed system is perfect.

just have them vent the ES, and evacuate the system and charge with the correct amount of ES under vacuum. you'll be fine.

it's best to have them give the car a hard vacuum of at least 30 minutes on the pump to remove any water from the lines due to the air in the lines.

Recap: Turns out there was a leak at the compressor O rings. As there are no instructions, indy used the yellow washer on the high side and red on the low side. It was leaking at the yellow washer. Although it held vacuum, it leaked out a week later under pressured on the yellow, high side. So he used the green on the low and the red on the high side (thinking red= high pressure). His boss wanted to charge me a half hour labor but I refused as it leaked out. As it is, I have to get 2 more cans of ES-12a.

So I'm getting 64 degrees at the middle vents (I rigged it open for A/C) in 90 ambient temp. Wife is happy, peace at last at home.

64 degrees seems a bit high for 90F outside.

In my 190E it'll get into the high 30-40s (ES-12a)

My dad's 300SD (Es-12A) gets low 50s..

Unless you're talking about vents temps with the engine at idle..

yes 64 is a bit high. even with max fan on a hot day I get upper 30's, unless idling in traffic. Are measuring at idle ?

These past few weeks have seen 85-95F up here. Only at a stop does my cooling system fail me, but once on the road above 2k rpm its nice and cold, I would guess 30-40s easily.

42 degrees at 77 ambient. Maybe I am overcharged. I will have to check.