As standard, on all modifications of the Renault 19 with rear drum brakes, a pressure limiter in the brake actuator is built into each wheel brake cylinder. These limiters are permanently adjustable and ensure that when you press the brake pedal with your foot, less braking force is transmitted to the rear wheels than to the front. This prevents premature locking of the rear wheels.
If, when checking the brake system, you found that the rear wheels are braked one-sidedly and blocked before the front ones, then it is necessary to have the brakes checked in a car workshop.