Aoa. Dear friends i have vitz 2015 1000 cc. I have problem in my car that with AC on and at low speed like 5kmph or on reverse my brakes become very hard and not working. I cleaned throttle body injector and plugs all are fine and also change the brake boster but problem remain same. Mechanic told me that car has weak engine but there is no symptoms of weak engine. Kindly help
