97 GMC p/u vibration when braking
i have a 1500 w/ a little over 190,000 miles. when braking it shakes really bad from side to side. when i'm almost stopped it no longer shakes side to side, but i can feel it pulling forward then backward a little (make sense). like there's a low/high spot on the rotor and it's grabbing w/ every rotation. visually inspected the rotors and they appear fine and i can't duplicate the grabbing action by spinning the rotors myself. does this sound like a problem with the brakes or steering? forgot to say the the steering wheel shimmies back and forth too when braking. my father in law (who is a mechanic) told me about a year ago to put some grease in a grease fitting attached to the steering mechanism, but wasn't very specific about what/where. just said 'do it'. so i don't know if this problem is related to brakes or steering or both. any help ya'll can provide would be great. you've steered me in the right direction before, so I'm sure you can do it again!