Had small loss of
coolant from my
Yanmar 4JH3-TE for years. Not a big problem, the
antifreeze lost just makes a mess on and under the
engine.
Now have re positioned the header tank. Previously mounted on a bracket bolted directly to the
engine. Now, using the same bracket, just turned around, mounted on the side wall near the engine. Problem solved.
I think that the
water in the header tank was atomising at certain engine vibrations and exiting via the header tank overflow. It was not obvious where the
coolant loss was coming from.
Whatever, this seems like a 100% cure and all you need is a suitable fixing bolt. Recommend this if your header tank giving a
water loss problem.
Peter