Coolant Leak

I haven't experienced this problem in my 912iS but I did in a 912ULS.  A simple tightening of the hose clamp solved the issue.

When I installed my 912iS I used Gates heat shrink collars (PowerGrip) over the hoses and fittings.  I have never had an issue with any leaks.  This may not be available if you have a SLSA but mine is an ELSA.

https://www.gates.com/us/en/search.p.7405-000000-000000.html

My understanding is that spring clamps are better than worm clamps on coolant hoses.  Spring clamps can expand and contract if/as necessary and still apply constant pressure.  Worm clamps can be overtightened and cut into the hose, their adjustment slots can fray the hose, and they won't compensate for any compression/shrinkage of the rubber over time. 

You can use Norma Torro CT constant tension worm drive clamps. They adjust as temperature changes and also if the hose deforms. They are used by some car companies for their cooling systems.

Thank you for all of the advice.

The leaking hose issue is solved.  On a related matter... I flew 8 hours the other day (4 hours each way).  When I took off the cowling last eve I noticed there was lots of white dried coolant "Spittle" (can't think of a better word) around the coolant filler cap. The cap was tight.  And, when I removed the coolant cap, the coolant level was right up to the cap.  The engine temps were fine throughout the flight so there were no engine temp spikes nor prolonged ground run-ups.  

I think I should bring the plane in and get a coolant system pressure check.  What do you guys think is going on? Thanks again.

Are you talking about the pressure cap or the cap on the overflow tank?