Well, let's see now, Dave M. As I pointed out, my 87 300D cylinder head cracked in the COMBUSTION chamber resulting in an entire loss of coolant within a few miles. I was driving the car @ 75mph when this occured. Later, at the MB dealership, the technican poured water into the cooling system, I started up the motor and water shot up out of the expansion tank. That 22:1 compression has to go somewhere!
The MB maintenance manual cooling system test specify's a pressure test of 1.0-1.3 bar. Of course the rest of the MB maintenance manuals, (3) could contain more misinformation, too.

Your right, Dave.

After 12 years and 177K of owning my 1987 300D I'm wrong.

I'm outta here!

Ed.