(06-28-2020, 08:39 PM)Grumpy Goat Wrote:(06-28-2020, 05:10 PM)mspratz Wrote: I have come across at least one procedure in the Haynes manual that I think is inadvisable. After draining the coolant, the Haynes manual says to simply fill the radiator back up, shake the bike from side to side, top it up, run the bike until warmed up. Allow it to cool, and the check and top up as needed. On the ADVRider forum a guy complained he drained 1.5 Litres out of his cooling system and could only get 1 Litre back in using the Haynes approach. The problem is, because of the shape of the cooling system as a whole, the Haynes approach is going to leave bubbles of air in the system which are impossible to expel, and will lead to hot spots in the engine. The BMW manual says to use a vacuum-fill approach. The BMW tools cost a small fortune, but alternatives, such as the UView Airlift, can be had for US$150 or less.
Sounds like a great tip. Thanks Michael. Here is a link to the UView Airlift on Amazon.
I have a coolant vac system that uses an air compressor to pull a vacuum on the system and then introducing the new coolant in it eliminates any air pockets. Used it on my C4S and worked great, would think it would work well for this application also.