Vibration under braking

Got abit of problem under medium/ heavy braking the old disco 1 has a very uncomfortable vibration I first thought it was a brake judder but now't through the pedal. I have looked and have a pair of knackered radius arm bushes. These I am replacing over the next few days. My question is is there any other reason that will cause this problem. Ta

Once upon a time I had a juddery feeling in my brakes, especially if I braked hard from about 70 mph. I thought it might be warped discs but they appeared to be running true. Eventually I changed the brake pads and it went away over the next few weeks. I don't know why those particular pads were making it judder but it wasn't something I'd considered. So maybe worth mentioning.