Hi I have a 99 f-150 4.6. I just replaced my water pump flushed coolant and flushed heater core. I drove the truck with prestone flush and had very good heat. I drained the system and ran clean water through the degas and drained again and filled with coolant. I have been trying to burp the system with no luck. Now I am wondering if I didn't put my heater hoses on the wrong heater core nipples. I put the hose coming out of the intake tube on the right nipple and the hose coming from behind the engine on the left nipple facing the firewall. Is this correct? thanks

 

You still have air in the system. Borrow or buy an AirLift system and you will never look back.