For monitoring coolant-levels, do you only need to check the overflow reservoir or is there a radiator cap somewhere.

[2004mountaineers]

For monitoring coolant-levels, do you only need to check the overflow reservoir or is there a radiator cap somewhere. The reason
I ask is that I have had vehicles for which is was NOT sufficient to just check the reservoir; it was actually possible to end up with a completely
full reservoir and a dry-as-a-bone radiator (VERY BAD....)

2004 Mercury Mountaineer, 4.0liter, v6, 'awd'.

 

[Mbrooks420]

You want to monitor the reservoir level. If there’s no air trapped in the system, and the overflow tube is clear, the reservoir will be the most reliable way to keep track of the level.