1. Faulty Brake Light Switch: The brake light switch, also known as the brake pedal switch, is responsible for activating the brake lights when the brake pedal is depressed. If this switch is faulty or not adjusted correctly, it can cause the brakes to momentarily disengage when the pedal is released.
2. Vacuum Leak: If your van is equipped with a vacuum-assisted brake booster, a vacuum leak can cause the brakes to lose power and fail for a split second. Check the vacuum lines and connections for any leaks or damage.
3. Brake Fluid Level: Low brake fluid can cause the brakes to become spongy and less responsive. Check the brake fluid level in the master cylinder and top it up if necessary.
4. ABS Module Malfunction: If your van has an anti-lock braking system (ABS), a malfunction in the ABS module can cause the brakes to temporarily fail. Have the ABS system diagnosed by a qualified mechanic if you suspect a problem.
5. Electrical Issues: Faulty electrical connections or wiring issues can also lead to intermittent brake failures. Check the electrical connections related to the brake system, such as the brake light switch connector and the ABS module connector, for any loose or damaged wires.
Since the issue happens only once a week and at low coasting speeds, it's likely an intermittent issue. It may be helpful to take the van for a test drive with a qualified mechanic to observe the problem firsthand and provide a more accurate diagnosis.
