What's the reason for the air pump not building up pressure?
2 Answers
Here are the reasons why a car air pump fails to inflate: 1. The built-in reed in the air pump has softened over time, preventing it from springing back when the air reservoir reaches a certain pressure due to back pressure. 2. The air pump hose is clogged. If it's just a hose blockage, it's easy to check by disconnecting the hose from the dryer and starting the pump. If black smoke-like substances come out of the hose, it indicates a blockage. The solution is to replace the air pump hose. 3. There is a leak in one of the four circuits, causing the four-circuit protection valve to close automatically. Check if one of the pressure gauge needles can reach 6 pressures. 4. The built-in spring in the four-circuit protection valve has rusted and become stuck due to prolonged use.
Over the years of repairing cars, I've encountered many cases where air pumps fail to build up pressure, mainly due to issues in the air system. Common problems include loose or broken pipe connections, which allow air to escape directly and prevent pressure buildup; aging seals inside the air pump that leak air as soon as it operates, making it impossible to build pressure; sometimes valves aren't closed tightly or are blocked, disrupting airflow; or it could be a power issue—if it's an electric air pump, a dead battery or poor wiring contact can prevent it from working properly. I recommend first carefully inspecting the pipes and connections for cracks or looseness, and ideally trying a new seal. If that doesn't work, consider whether the pump itself is broken or if it's being misused, such as operating too quickly and overheating the motor. Regular maintenance can prevent these issues—don't wait until you're in a pinch with your vehicle. It's safer to have a professional take a look.
