To replace a Chevy oil sending unit, open the bonnet of the vehicle and identify the oil pressure switch on the engine block. Use the jack stand to support the vehicle once it is elevated. Disconnect the electrical wires from the oil pressure sending unit and remove it carefully. You will need a jack stand, a set of wrenches, a floor jack and a driver ratchet to perform the task.
Depending on the type of the vehicle, the pressure sending unit has different allocations and shapes. After disconnecting all the electrical wires, carefully press the connector and pull it out. Use a wrench to loosen the pressure sending unit. Prevent any unnecessary leakage from the sending unit by covering it around with Teflon tape.
Use your hands to screw the oil pressure sending unit, and then tighten it firmly using the oil pressure switch socket. Take caution while screwing to prevent over tightening, as this causes breakages.
Fix the electrical wire connectors to the new oil pressure sending unit. Put the connectors and the sending unit into place until they match together. Inspect the new oil pressure sending unit for oil leaks by starting the vehicle. Examine the pressure gauge to be sure that it is performing correctly.