You bought a new hand pump but found that the hand pump does not suction oil when it is working. Even if you press the handle of the hand pump repeatedly, the hand pump starts to suction oil, and the oil intake is much less than normal. Please don’t worry, this is because there is a shortage of oil inside the fuel tank of the manual pump and it has not been used for a long time, and air has entered the inside of the plunger of the manual pump. At this time, we need to bleed the air inside the plunger, and the manual hydraulic pump can work normally.
Let’s take a RIVERLAKE P-462 two-speed hydraulic hand pump as an example, in order to completely expel the air inside the hand hydraulic pump plunger, please follow the steps below:
1.Fill the manual pump oil tank with hydraulic oil, connect the manual pump, hydraulic hose, and hydraulic cylinder
2. Turn the air release valve clockwise to open the air release valve
3. Rotate counterclockwise to loosen the air release screw of the plunger, turn on the manual position valve of the manual pump, and press the handle repeatedly to discharge the air inside the piston. When the air is exhausted, tighten the plunger bleed screw by turning counterclockwise and wiping the surface of the hand pump with a rag.
4. Now that we have expelled the air from the hand pump piston, we still need to test the hand pump to confirm that the problem has been solved. Turn off the hand pump switch, retract the hydraulic cylinder, turn the hand pump switch back on, and press the hand pump handle repeatedly, the first need to press The force of the hand pump will be relatively large, and the hydraulic cylinder piston will also start to rise rapidly. This is because in the first stage of the two-speed hydraulic pump, the larger plunger in the hydraulic pump works; once the piston rises to the maximum height, the pressure reaches the first stage. The pressure required for the second stage, the force required to press the handle is greatly reduced, because the smaller plunger in the hand pump starts the second stage pressurization work. After the test is completed, if everything is normal, it means that the air in the hand pump has been completely discharged.