What are the reasons for the air pump making noise but not inflating?

[DiRuth]

There are 4 main reasons why a car air pump fails to inflate: 1. Softened internal spring plate in the air pump: The back pressure from the air reservoir prevents the softened spring plate from bouncing back up. When the air reservoir reaches a certain pressure level, this back pressure will keep the softened spring plate from functioning properly; 2. Clogged air pump tubing: This is easy to check - simply disconnect the air pump tube from the dryer side and start the pump. If black smoky substances come out from the tubing, it indicates a clogged air pump line. The solution is to replace the air pump tubing; 3. Air leakage in the four-circuit system: The four-circuit protection valve automatically closes. Check if one pressure gauge needle can reach 6 units of pressure while the other shows no pressure at all; 4. Malfunctioning water tank valve: This causes air pressure to leak from the water tank. The inspection method is to hold the water tank's intake pipe while pumping air. If inflation becomes possible, it means the valve is completely damaged.