If I would like to change the rubber seal, anyone please know where I can get a new seal? or may be a new cap?
You don't need to, your fluid level is too high, see my previous post
As you put the cap on & the float submerges it's burping the excess through the vented cap
It's not actually the case. It may be just the camera angle.
The fluid level is below the max line mark (with the float submerged in)
Yes, my fluid level WAS too high when I bought the car and the leakage was much worse, but now I withdrew some fluid out so the level is below the max line (but it does still leak). In fact in most roundabouts and RT corners the red brake light comes on. So the the fluid shouldn't be any lower.
