Proper coolant amount & draining??
My Cousin decided to replace his radiator in his 1986 BMW 325e. It's an automatic. It's been a good car for him and a gas saver as well. First he drained the fluid from the old radiator and the expansion tank. (there is no radiator cap on the radiator for this model). He then ran a flush and drained all that out. I told him he should drain the fluid from the engine black as well before the flush. He said the manual didn't have that as a step when draining/refilling your coolant system. He proceeded to refill his cooling system and new radiator with the correct amount of water and antifreeze ratio but half way through that, the reservoir stopped taking fluid. He tried to burp it for hours and bleeding it from the screw on the thermo housing etc still the fluid wouldn't go down. And no fluid or air bubbles came from the bleeder screw. I think it matched the amount that was still in the engine block, so it's just full. He disagrees. He's not driving it at all until this gets figured out. I told him to start over and drain all fluids this time. Who is right?