We got the aftercooler fitted and we are ready to fill it up with coolant/water. Do you guys just fill at the top cap?

 

Yes, fill with distilled water and a capful of water wetter. As it fills, turn on water pump, squeeze coolant lines from heat exchanger to aftercooler. This will help "burp" the system. Top it off, and check frequently.

 

Install instructions say to fill up to just below the threads of the plug to allow for some expansion of the water.

 

CoolGuy094, does this look too low then?

https://www.youtube.com/watch?v=dEgXfwjmMcY

This is my setup.

 

That's right where my level was. Right at the bottom of the threads. Looks good to me.

 

Good to know . I'll probably do what Kenny_Stang suggested as I'm still at 120-130F cruising in 80f days.

I might need to switch to 1/2 distilled water 1/2 Coolant and some MoCool from MOTUL.