Originally Posted by
sawdust_128
Michael, Good to hear theat you are making progress. Have you checked the lines/hoses going into the expansion tank. If they are original, they are about 15 years old. There were a bunch of folks here who experienced the old hose syndrome on their coaches. What you are describing with "mysterious" coolant loss and failure to start and run is exactly what happens after these hoses have become brittle and cracked. They are pretty well strapped in place so the cracking, altough severe does not get a chance to open up. You don' see the leak because when you stop and shut down to park, everything starts contracting. When you start up, it takes time to warm up enough to start to drive coolant out of the system. Going down the road, the leak is persistent, but slight and the road draft and fan draft dries it. The only way I found mine was I tracked back on a single drop and started pushing the hoses, it then opened up and I could see active leak.
Good luck