Q: How to replace a extension housing oil seal on Ford F-250?
A: To perform the fuel pressure test, obtain a fuel pressure gauge and adapter set (fuel line fittings). After relieving the fuel pressure, lay a shop towel over any fuel connection to be disassembled to absorb the residual fuel. For the preliminary inspection, check the fuel system's delivery by listening at the fuel filler opening while an assistant turns the ignition key to the On position (engine not running). If no sound is heard, check the fuel pump fuse, relay, and circuit. If there's still no sound, there may be a problem in the fuel pump circuit or a faulty fuel pump. Check for battery voltage to the fuel pump relay connector and power relay connector. If present, have the relays tested at a qualified automotive repair shop. If no voltage is present, check the fuses and wiring circuit. For the operating pressure check, attach the fuel pressure gauge to the test port and activate the fuel pump without starting the engine. Note the fuel pressure and measure it again with the engine idling. Detach the vacuum hose from the fuel pressure regulator to check for an increase in pressure. If pressure is too high or low, inspect and replace components accordingly. For fuel pump replacement, remove the fuel pump/sending unit assembly from the vehicle carefully and install a new rubber gasket during reassembly. Adjust the angle and travel distance if the float arm and float wire loop were damaged during removal and installation. To replace the extension housing oil seal on 2WD models, raise the vehicle on jackstands, remove the driveshaft, flange/yoke nut, and washer, then remove the dust shield. Carefully pry out the old oil seal and bushing, using a special removal tool if needed. Install the new oil seal, reinstall the dust shield, and reassemble the driveshaft, flange/yoke, and nut. Lubricate the splines and driveshaft sleeve yoke, then install the driveshaft and lower the vehicle.