If the pneumatic air booster pump does not work properly, there are several possibilities:
(1) drive the piston seal to wear, resulting in the side and bottom side of the piston.
(2) the damage of the control valve causes the reversing valve to not work properly.
(3) the reversing valve is too dirty, or its seal is damaged, resulting in its inability to move.
(4) the two piston connection is damaged, the pin pin is off, and the two piston rod is misplaced, causing the piston rod to not move.
(5) the pressurized cylinder seal is leaking.