L series problem

Had an ird pipe burst which emptied the coolant,pipe had gone just below the hose clamp. I cut an inch off it and refitted it. temporary measure,it needed a new one really. So just filled the cooling system with water,seem to struggle getting it bled. Got it circulating but when the system pressurised all the water would disapear from the expansion tank into the rest of the cooling system which indicated an airlock somewhere. But no matter how much I bled the system it made no difference. Drained the system later and changed the ird pipe, which highligted a leak on the ird cooler[separate thread] cured that [hopefully] Filled the sytem with coolant. Still the same issue with bleeding. Then Today it blew the bottom hose off. Confused. A lot of pressure in the cooling system but the expansion cap should sort that, it does hiss regularly. Seems to point to a blown headgasket, but no smoke from exhaust,no water in oil, no oil in water and no loss of coolant. But this excess pressure could be from combustion gases me thinks/

Head or gasket knackered

I am changing the head/gasket , any tips??? Gratefully received.