When replacing the CTS, how much coolant should be drained from the radiator to avoid spillage when removing it from the intake manifold. Also, if no coolant is drained beforehand how much will spill out? Are we talking someone opened up a faucet or a small trickle?

The reason I ask is because I live in a neighborhood with a stupid HOA who have strokes over spilled milk.

 

I would drain it all the way down to avoid any spillage.

 

When I replaced mine only a little bit dripped out maybe 2 measuring cups worth but this could also vary for you but if you dont want to drain the whole thing I would just place a typical oil drain pan under the front of your motor and take the sensor out you should be fine