i have a 89 240sx hatch with z32 brakes all around. everytime i start driving, for the first 5 minutes or so, the brakes dont work. i slam on the brakes and the car slows down but its really really slowly, i almost crashed into the car in front of me today on a red light, and i wasnt even going fast. after a few times i slammed the brakes a few times it starts getting better until its normal (the wheels lock when i slam it, its what its supposed to do, dont have abs)
its feels like the brakes have to get to optimal "operating temperature" before they start working. wtf?

any help would be appriciated

-Peter