1996 bmw 735i. How do i bleed the cooling system and free it from air?

Only had this car 24 hours and the temperature shot up quickly after an 80 mile journey. The expansion tank shot the lid off as this was the weakest point. I have replaced that but the system is still overheating and water is coming out from somewhere. I need to bleed this of air and try to locate the leak. I`m hoping it is not the rad or water pump and just a hose but if anyone can help me, i would be very grateful. The car is the 1996 E38 steptronic 735i model. Thanks.1996 bmw 735i. How do i bleed the cooling system and free it from air?It sounds like a block in the radiator. I would remove radiator and flush it out and then get it pressure tested. This is why I think your lid shot off. Once you replace the radiator fill with anti freeze and run the engine as it warms up the thermostat will open and you just continue adding anti freeze until the radiator and engine are full. It is also a good idea to have the heater operating while you do this to ensure the whole system is flushed. Then just top up your reservoir tank and hopefully you will be motoring on :-) all the best1996 bmw 735i. How do i bleed the cooling system and free it from air?It could be the thermostat. As to your question- this test will solve the problem and answer whether it is the thermo. With the car cold take of the radiator cap. Have some water ready. make sure the radiator is full. Ignor the overflow jug for now. Start the car. As it warms up the thermostat should open and you will begin to be able to see flow through the open cap hole. Keep adding water as the leverl goes down. Eventually the level and flow will stabilize. If you have not overheated after a half hour, you likely won't. One more thing- check to see that the fins of the radiator aren't plugged with bugs and crud. If it passes, drain out some of the water and get a proper balance of antifreeze back in.