To properly bleed your Pantera's cooling system...
- Jack the REAR of the car up as high as you can.
- Remove the cap on the pressure/swirl tank and top off the coolant.
- Open the bleed valve on the radiator and allow any air to escape. Hold a rag there to avoid a mess. When it stops bubbling and is mostly water, close the valve.
- Top off the pressure tank again if necessary and put the cap back on.
- Start the engine, let it idle and rev it a few times for about a minute. Then shut it off.
- Return to Step 2 above, and repeat 3-4 times.
This should clear out all the air trapped in your engine.