I need to remove "all" the antifreeze from a 1989 E150 4.9 and replace it with antifreeze that's for aluminum and it says any old fluid left in the system will contaminate the new stuff and void the new radiator warranty. The old radiator is out so I need to get the old stuff out of the heater, motor and hoses. Thanks

 

Have to get it flushed, you can't do it at home, I tried this with my 99 350, parked on a hill, backed up the hill, got about 3/4 out of it, at least according to the manual. Now mine had the green in it, my radiator was aluminum and plastic, my modular engine block is iron, everything on it is aluminum. It's not that there is a non aluminum coolant out there, but what I do know is contaminates from engine operation turn antifreeze caustic, that is why they have a date on them requiring change, the 3 year stuff will get corrosive if left longer. Why else do you think radiator, heater cores and engines plug up, along with the core plugs rot out from the block?

 

Thanks, off to the radiator shop then.