It is not a reliable bleeding method.I have been following Mangos guide on how to bleed
The upper hose is seating higher than the ET coolant level, and so you will never be able to fill it up until you run the engine. This is why I don't like the Mango method. I run the engine during bleeding coolant.after changing expansion tank job I did not bleed it properly because I couldnt get the upper hose to fill with coolant.
Don't do this, as if you run the engine to operating temperature with the tank cap opened then there is a chance the coolant boiling in the head and causing damage. But if you run engine with cap closed then you cannot open the cap (as the BMW label says "Attention do not open the cap when hot".i should have brought the car up to temp before bleeding.
How could the hose pop off? It is impossible with the metal locking clip in place, unless the hose connector broke off.Causing the upper hose to pop off and shoot the coolant all over the hot engine bay.
It seems to be a drama doing the coolant bleeding, and it shouldn't.through my efforts today I got the hose on pretty well. kept bleeder and top off while I filled coolant. realized the thermostat needed to be warmed again after the pressure popped.
I believe I will be able to bleed it the correct way in the morning considering I got it up to operating temp and circulated coolant.
sorry if this is confusing I am high and can clarify in a couple hours. Thanks.
you can try my method as it has not failed yet for me and some others who had tried.
1) engine cold, car head up on slope driveway or flat ground level is fine.
2) remove bleeder and tank cap, fill coolant to the MAX marker on the tank using the popper rod as indicator. Do not fill up to top of tank.
3) close the bleeder and screw the tank cap by one turn to avoid coolant shooting out later when running the engine.
4) Set heater to hot and fan low, run engine at idle, then rev it up to about 2500 RPM a few times to push out any air pockets into the upper hose. Important: Do not let engine running more than 7 minutes total while the tank cap is not closed, to avoid damaging the cylinder head. Keep engine idling.
5) Crack open the bleeder to let air out and close it when no more air bubbles. Top off the tank to MAX marker. Close the tank cap.
6) Test drive and check for having heated air in cabin. Done.