I drained and re-filled the radiator on my '03 DMAX today, and noticed that there is an airbleed screw on top of the thermostat housing. The Helms manual does not seem to mention much about it, but the diesel supplement that came with the owners manual says to use it if the coolant tank becomes empty from an overheated engine. Obviously mine did not over heat, but I am filling an empty coolant tank. Do I need to loosen the screw and bleed air out?

Scott, you can loosen that screw, but you will still likely have some air trapped if the system was low. I find that it usually takes almost 30 miles of driving to completely purge the air out of the system, even after filling with the screw loosened.

Thanks for the quick reply Eric. I'll leave the screw alone and drive it for a while to see if it purges all the air out.

Take some coolant with you I find the same about 30 miles or so and refill.

Maybe FASS or Preporator make something to take the air out so that it cools more efficiently and makes more HP.http://www.dieselplace.com/forum/smileys/smiley4.gif