Well...I made it.
7 hours and 60 litres of water to cover 420 km the bus travelled from Jasper to Red Deer.
We stopped every 100km to let the engine cool and add fluids. I did not know at the time but the rad cap was shot so the coolant was steaming out.
Replaced the viscous clutch with an electric clutch, new rad cap, thermostat and water pump.
Bus is running at 180, much better than 235
Now to install a toilet.
Thanks to ETR trucking in Red Deer for fixing me up.