Brake problem
 

I just picked up this 91 accord lx 5 speed about a month an half ago and it needs some work but the price was right. So I've noticed when im on the freeway doing the speed limit and get on the brakes hard it shakes real hard like rotors are warp bad. Heres where i need help if im doing the same speed and ease into the brakes its has almost no vibration what so ever so what do you guy think?

Sometimes new pads, lubing the caliper pins, and new pin seals will reduce vibration to acceptable levels.

Otherwise new rotors are necessary. See DIY forum for guidance on replacing rotors. Ericthecarguy has a nice video on youtube for this operation, and others also.

good luck

on a car that old, could also be wiped out suspension components. ball joints, tie rods and possible even motor mounts.