There's no fixed timeframe for how long our vacuum mounts will hold. It depends on various factors such as the surface you attach them to, the condition of the vacuum mount, the weight it's supporting, and other variables. When it comes to the surfaces, vacuum mounts were originally designed for carrying large sheets of glass and other smooth, flat materials, so smoother surfaces work best. Keeping both the surfaces and the SeaSucker clean will help maintain a strong hold.In case the vacuum mount begins to lose suction, it has a warning mechanism. As you may already know, the vacuum pump's plunger will automatically extend from the pump cylinder when it starts losing suction power. When you notice the orange indicator band, it's a signal to repump your SeaSucker. For car racks, it's generally advisable to check the rack before getting into your vehicle and inspect it each time you make a stop for gas, food, or a bathroom break.