Rover V8 overheating - Expansion tank dry

[Chuck21]

Hi folks. My buddy has a Cobra rep on a Rover V8. It overheated on a drive, no issues driving but water temp through the roof. Took a look and no obvious leak but expansion tank dry. Is most obvious issue a minor leak from a hose or similar that wasn’t noticeable as it would just evaporate in/from the engine bay?

Any advice welcome, thinking we just fill up from the header tank, start her up and watch for leaks?

[Chuck21]

Yeah, oil is all clear.

We drained it from the rad bottom hose (not a lot came out) and re-filled then ran it for a good while. There was the odd spike but overall it stayed in range. As you say I think the next step is to fully pressure test to make sure there aren't any other issues.