as above, when im driving and slowing down theres a real nasty clunck not a little one a big one

from the drivers side wheel area, and my brake pedal feels like it getting taken away from my foot


iv never felt anything like this before and it dont feel good
it also does it in reverse but the brake pedal is coming back and pushing my foot upwards

, i dont get whats going on

very strange and it feel like im driving over a brick when it happens
right iv jacked it up and and give the wheel a good shake and a pull and there nothing out of the ordinary

iv taken the bottom ball joint out to check for play but still feels nice and tight also the track rod and thats good also, all the bushes are alright over that end to,
i cant find anything wrong

but there is somthing seriosly wrong somewere, it doesnt happen everytime or if im trying to make it do it but it will happen a few times on a journey,
any help would be great as im baffled and i dont trust my kids in the car now
thanks diesel