tallyman:
To be fair, the breakdowns (there were around 5 I recall) were nothing to do with the units, it was down to not being refuelled correctly - due to having been stood for a while before putting on the road there was not as much gas as the gauges said. Once the refuelling system is running correctly there hopefully won’t be any more issues.
When they where new we had to initially hook up a breather pipe until they settled down, the other option is to vent the tank. I actually did tell the Swindon guy that there can be false readings due to them being stood or when the weather is warm and the liquid vaporises and builds up the gas pressure, so to counter that you hook up the filler and vent the tank via the blow off pipe while it’s filling. This allows space for the fresh fuel.