coolant leaking from overflow tube

[Cutwater28GG]

Ive noticed that coolant is increasingly leaking out of the coolant overflow tube on a d4 260 resulting in low coolant. are their any known causes for why this occurs?
could the oil system somehow be pressurizing the coolant system?

 

[watson1987]

Yes it can, but that would mean there is a head gasket (or worse cracked block) leak that is allowing it to happen. Other signs of this would be oily coolant or white smoke coming from your exhaust, indicative of coolant making its way to your cylinders. There are dyes you can buy for oil to find leaks, one test would be to add some to your oil system and see if your coolant becomes reactive.

The better (read: cheaper) problem is simple overheating causing expansion and overflow. Have you checked your running temps? Recently changed your impeller?