Air pocket started losing heat found water pump was leaking changed that and thermostat still no heat?

sounds like you have an obstruction keeping hot water from getting into your heater core. check hose routing and on certain older cars, there is a shut off in the hose mostly meant for summer time. if the car was bought used with the condition you refer to preexisting, my bet is that the person that sold it to you used barrs leak. it often clogs the heater core and effectively blocks the hot water from circulating.