The 7.3L diesel engine has the Rexroth pump for fuel injectors' pressurization, which provides the highest level of diesel efficiency; the pump is behind the front cover, and the reservoir is on top. It supplies oil pressure of about 450 to 3000 psi in relation to the drive condition, and regulates oil pressure by a solenoid poppet valve. The PCM regulates the operations of injectors through programming injector timing and output depending on what the different sensors such as the oil temperature, the MAP and the BARO sensors indicate on the vehicle emissions and power. Removal involves the exercisin of some level of mechanical truculence, as it requires the removal of the Turbo and fuel filter/water separator assembly; before this, it is necessary to drain the oil from the reservoir, as well as the high-pressure oil lines, and finally the electrical connectors. The drive gear bolt cover and related parts are next to be unbolted to pull out the high-pressure oil pump. For 6.0L and 6.4L engines the procedures are the same as disconnection of the Turbo and IPR valve, the removal of the bolts from the pump cover and then the separation of the cover from the block. The installation of the oil pump must follow the removal procedures to the letter but there must be the provision of new gaskets and seals, the oil pump be fitted properly and tightened in conformity with the best torque.