Probably a dumb question. I read that this must be a fully pressurized cooling system since there is no radiator cap on either side, only at the overflow reservoir. What would be the procedure to refill with coolant? I see a bleeder valve at the top of the radiator hose. Do I turn out the bleeder while filling at the overflow reservoir? Do it while the engine is running or off? Do I fill at the bleeder valve and the reservoir? And it's obv too late now, but may be helpful in the future for myself, or for someone else with same engine, but how would you drain this system without having access to the radiator? Would you just pull off a hose on the bottom to drain it? I pumped a half gallon out of overflow reservoir but that wasn't enough so I got coolant everywhere when I pulled off that top radiator hose to replace the thermostat. Currently waiting for the new thermostat to arrive, hopefully nothing will be damaged by the coolant sitting on the engine.