Don't fill the water tank to the top, usually the alloy tanks have two grooves round them, bottom one is min water level and the top one is max, BUT, this can be hard to tell where your level is really at when trying to look into the tank, so your need to shine a light in there to be sure.
When you bleed the system, are you un clipping the water tank and holding it up high whilst doing this with the screw cap off? Also, you might want to check it's not just pure water to.
Ps, car looks good in the pictures.