What is the reason why the air pump cannot exceed 6 bars of pressure?
3 Answers
The reason why the air pump cannot exceed 6 bars of pressure may be due to motor phase loss, damaged air pump seals, or the pressure relief valve being set too low. Below are the detailed explanations: Motor Phase Loss: Motor phase loss prevents the motor from delivering its rated power, thereby limiting the maximum output pressure of the air pump (as the air pump pressure increases, the motor load gradually increases, and the power rises accordingly). In this case, the electrical circuit should be checked. Damaged Air Pump Seals: Especially if the piston head seal is damaged, it can cause air leakage between the high and low-pressure chambers. Most common air pumps are piston-type, similar in structure to hydraulic cylinders. The piston head has seals that, over time, can fail due to normal wear and tear or aging, allowing air to bypass between the high and low-pressure chambers, preventing pressure buildup. In this scenario, the air pump compressor needs to be disassembled, and the seals replaced. Pressure Relief Valve Set Too Low: For safety reasons, air pumps are equipped with a pressure relief valve at the output to prevent the risk of explosion due to excessive pressure. If this valve is set too low, the air pump will automatically shut off every time the pressure reaches the limit, manifesting as the air pump's inability to increase pressure. However, the air pump will continue to function normally otherwise.
My air pump also had this issue before, it couldn't go beyond 6 bars of pressure, most likely due to pump aging or sealing problems. Worn piston rings reduce compression efficiency, and carbon buildup or deformation of the valve plates can also affect sealing. If the air tank is leaking, the pressure definitely won't rise—try applying soapy water to the connections to check for bubbles. If the check valve is jammed by debris, air will leak backward. I once disassembled and cleaned the cooling system; clogged cooling fins can cause the machine to overheat and trigger automatic protection shutdown. Finally, check the pressure switch—incorrect settings can also cause premature shutdown. You'll need to troubleshoot each of these possibilities one by one.
It's quite common for air pumps to get stuck at 6 bars of pressure. I've repaired many machines with similar issues. Focus on three key areas: First, the exhaust valve - if the spring is fatigued or the valve plate is deformed, it will leak air when reaching a certain pressure. Second, cylinder wear - if the piston ring's sealing performance declines, it won't reach the calibrated pressure. Finally, don't overlook pipeline issues, especially aging seals in quick connectors or flattened air hoses causing airflow obstruction. Once I encountered a control circuit failure where the pressure gauge showed 6 kg but no air was actually being pumped in. I recommend first trying a replacement pressure gauge, then disassembling to inspect the pneumatic components.
