
One word of advice for when you are checking for leaks: It pays to run the engine up to temp and then really thoroughly check over all the pipes/hoses - get right underneath the van. I was losing coolant for a while and after quickly checking under the van for drips couldn't identify the source. Eventually I discovered a hole in one of the front to back coolant pipes which was only leaking when hot. The coolant was dripping down onto the exhaust and then evaporating before it could reach the ground.
With luck it'll just have been needing topped up for a while.
