Oil suction pump

An oil suction pump comprising:

• an oil storage cylinder, a pumping mechanism, and a cap;
• wherein the pumping mechanism includes a body mounted beside the oil storage cylinder, a drive rod accommodated in the body, a plug fixed on a bottom of the drive rod, and a pressure relief valve secured on a bottom of the body;
• wherein the cap is disposed on the body and the oil storage cylinder, and the cap includes a connector configured to connect with an oil tube and communicating with the oil storage cylinder, an end of the drive rod is extended out of the cap, and the drive rod has a press lever connected on a top thereof, the cap further includes a first air conduit communicating with the body and the oil storage cylinder, a first one-way valve assembly connected with the first air conduit and received in the oil storage cylinder, and a second air conduit defined in the cap, wherein the second air conduit has an inlet segment located outside the cap, an outlet opposite to the inlet segment, and an pump segment defined between the inlet segment and the outlet segment and communicating with the oil storage cylinder, the cap further includes a second one-way valve assembly accommodated in the oil storage cylinder and connected with the pump segment, and the second conduit accommodates a pressure reducing valve.