3.6 LITER. Sensor. A Sensor that detects the vacuum level in the power brake booster to ensure proper power brake operation, typically located in the vacuum line from the vacuum pump to the brake booster. Brake Fluid Pressure Sensor. Kit - P/B BOOS VACUUM. BOOSTER Check Valve. Brake Fluid Pressure. Power Brake Booster Vacuum. Included with: Power booster.