There is bleeder on the top of the head where the hose goes in the top and and one in the back cross-over cooler in the back of the tunnel. Start the sled and run it, lift the back up about 1 1/2 feet and open that bleeder, air should start coming out, if nothing comes out, but coolant, then let the back down and lift the front up 1 1/2 feet and open that bleeder on the head some trapped air should come out of there. You might have to repeat this a few times, as you do, feel the running boards they should start warming up as the air is bleed out. You could also open the cap on the main hose, wait til it cools to do this, then run the motor to see if the coolant moves, if it doesn't you might need to replace the waterpump.