Australian Car Repair Issues? Ask an Auto Mechanic for Answers ASAP
Is this a manual transmission? And I don't understand your issue about rolling forward or back when stopped, are you holding the brake pedal down and it acts like the brake is not working? Is the brake pedal excessively hard to press, or is it soft and drops to the floor?
so it is in the park gear, engine off, and it rolls without catching at all? There should be a park pawl in the transmission that engages on putting it in the park gear. Does it do this every time you park, or does it "sometimes" engage and sometimes not? Would you be able to demonstrate it for someone?