Equi-pressure pump for cleaning an engine

A pump for cleaning an engine, the pump comprising:

• a central block having a lateral passage defined through the central block, an axial passage axially extending through the central block so as to be perpendicular to the lateral passage, an L-shaped first path, an L-shaped second path, a first parallel channel, a second parallel channel, an upper hole and a lower hole, wherein the L-shaped first path and the L-shaped second path are divided by the axial passage, a first distal end of the first path extends into the lateral passage and a second distal end of the first path extends into the axial passage so that the first path communicates the lateral passage with the axial passage, a first distal end of the second path extends into the lateral passage and a second distal end of the second path extends into the axial passage so that the second path communicates the lateral passage with the axial passage, a first hole and a second hole are defined in a side face defining the lateral passage to communicate with air outside the central block, a sealing ring is provided in two distal ends of the axial passage;
• a first sleeve securely connected to a side of the central block and defining therein a first chamber and a second sleeve securely connected to a side of the central block to be opposite to the first sleeve and defining therein a second chamber, wherein the first hole communicates with the first chamber and the second hole communicates with the second chamber, a shaft is movably received in the axial passage and has two protrusions respectively formed on a mediate portion of the shaft, a first piston head is securely mounted on a first distal end of the shaft and a second piston head is securely mounted on a second distal end of the shaft, the first piston head is received in the first chamber and the second piston head is received in the second chamber so that the first piston head and the second piston head are able to seal the first chamber and the second chamber in an air-tight manner;
• a first sealing block securely connected to the first sleeve and defining therein a first receiving room in communication with the first chamber, an upper room in communication with the first receiving room for receiving therein a first ball and a lower room in communication with the first receiving room for receiving therein a second ball;
• a second sealing block securely connected to the second sleeve and defining therein a second receiving room in communication with the second chamber, an upper room in communication with the second receiving room for receiving therein a third ball and a lower room in communication with the second receiving room for receiving therein a fourth ball;
• a moving element that is received in the lateral passage and has an H shape in cross section, the moving element has two protruded portions respectively formed on opposite sides of the moving element, each of the two protruded portions has a seal mounted therearound and a cushion mounted on a center of the protruded portion, a button is provided on opposite distal ends of the lateral passage and has a rod extending therethrough to engage with the cushion of opposite sides of the moving element to respectively engage with the cushions, the first hole defined in the central block communicates the lateral passage with the first chamber, the second hole defined in the central block communicates the lateral passage with the second chamber;
• wherein a first connector is inserted into the upper room of the first sealing block for connecting to an oil reservoir, a second connector is inserted into the lower room of the first sealing block for connecting to an oil outlet of the engine, a third connector is inserted into the upper room of the second sealing block for connecting to an oil entrance and a fourth connector is inserted into the lower room of the second sealing block for connecting to a cleaning solution, a air hose is inserted into an upper hole defined to communicate with the lateral passage for connecting to a pressured air such that by driven of the pressured air, the first and second piston heads are able to move reciprocally back and forth and contaminated oil together with the cleaning solution is sent to the oil reservoir and the internal of the engine is cleaned.