bleeding coolant question

[tjsands12]

i just put in a rear heat exchanger from bender racing and bled the rear exchanger. then i tried bleeding the front, by the on/off switch for the carb coolant, and cant get any coolant to bleed out. i did this all when the sled was turned off. do i need to run the sled in order to bleed out the air???? whats my next step??

 

[rx1jim]

The way I bleed the air out of the cooling system is to raise the rear end of the sled up so it is at the same height as the coolant bottle fill opening. Remove the bleed screw from the new heat exchager and continue to fill the system until coolant comes out of the bleeder port on the new heat exchanger. Run the sled in this position and the air in the system will get trapped in the top of the new heat exchanger. You will have to do this a few times. Once you get most of the air out, running the engine will displace the air to the coolant bottle. I use a 50% antifreeze with 50% distilled water mixture. This concentration provides more than enough freeze up protection for where I ride. Keep in mind the more antifreeze you have in the solution, the poorer the heat transfer will be.

 

[Todddob]

Also start your sled on a tilt trailer, rad cap loosened up, then tilt it, engine up in the air. It will force the liquid down to the rear heat exchanger and the water pump will circulate and all air will go up and out.