Here is the filling procedure. It is self bleeding so if you are still getting air, you may have damaged a head gasket when you overheated it with the water pump problem.
First clean system to remove old glycol, see Cooling System Cleaning / Flushing.
Fill system with 50/50 glycol/water mix. The thermostat in the these engines allow air to flow through them.
Continue filling system until full, this provides better heater performance. Be careful not to spill coolant on drive belts or the generator.
Fill coolant recovery/reserve container to at least the FULL HOT mark with 50/50 glycol/water mix. It may be necessary to add coolant to the recovery/reserve container to maintain coolant level between the FULL HOT and ADD mark after three or four warm-up/cool down cycles and also, if any trapped air that has been removed from cooling system.
Sunday, January 16th, 2011 AT 4:30 PM