Max Damage

So, does this overflow pull coolant back into the radiator when the engine cools?? Or is it just a catch bucket for when you overfill the radiator?

Although I realize this thread is old (or not new anyhow ;~) I can't help but add my 2c. It important the rear brakes (if they are drums) are adjusted correctly. If the rear drums have too much slack before engaging, it becomes hard to properly bleed the brake.