Im planning on replacing my old fan switch with a new 178 on 168 off switch and since i have to drain the radiator im gonna try and flush it too. I pour the solvent into the radiator and let it heat to normal temp and then drain it right? I just want to make sure i drain as much as possible and this is where im unsure of what exactly to do. Thanks

 

Yep. Let it reach operating temp & run it a bit longer, to ensure that the Flush solvent gets routed throughout the system good & does its job, then drain & refill. Some people drain & refill twice, to get more Flush solvent out of their cooling system.

 

How do i ensure im draining all of it and not whats just in the radiator? Should I use water then the first time i refill? Coolants expensive