It wouldn't hurt to put a screwdriver to all the hose clamps to ensure their tightness. This is simple and quick.
The cap and a good check of the hoses and clamps would be good preventive maintenance that will very well fix your problem.
One other thought, if you're trying to keep the rediator absolutely topped off, you will lose some to expansion when the engine warms up, especially this time of year. Just a thought.
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
[This message has been edited by LarryBible (edited 07-26-2000).]