I had a brake problem where my car would tend to fishtail when i brake hard. It may be one of the rear wheels skidding. I gave the car to a mechanic and he asked me to replace the rotators and pads to fix the problem. But even with new original rotators and pads, my car still tend to spin / skid if i press the brakes really hard for an immediate stop. I asked me mechanic and now he's telling me it is because my car doesn't have ABS. He also says that it is due to the fact the rear wheels doesn't carry much weight as the front wheels. Is this normal? Or could be a problem with the brake proportioning valve?

No that is not normal to skid it never did it when it was new did it. If the rear brakes are shoes they may have been put on backwards that will make them skid. Something is not right Take the car to another mechanic who has more brake experience, God Bless

No that is not normal to skid it never did it when it was new did it. If the rear brakes are shoes they may have been put on backwards that will make them skid. Something is not right Take the car to another mechanic who has more brake experience, God Bless