The fuel pump is in the fuel tank. Depressurize fuel system. Disconnect battery ground cable. Raise and support vehicle. Remove fuel tank, then fuel sending unit and pump assembly by turning cam lock ring counterclockwise. Lift assembly from fuel tank and remove fuel pump from fuel sending unit. Pull fuel pump up into attaching hose while pulling outward away from bottom support. Take care not to damage rubber insulator and strainer during removal. After pump assembly is clear of bottom support, pull pump assembly out of rubber connector. Reverse procedure to install. Some 1985 truck models equipped with electric fuel pumps may experience a no run or no start condition and/or a blown fuel pump fuse. This condition may be attributed to an inoperative in tank fuel pump caused by a short in the radio frequency interference (RFI) filter. The RFI filter is located on the electrical input terminals of the fuel pump . To check the above mentioned complaint, disconnect the three wire connector at the fuel tank and measure the resistance between the two outside wires (black and tan) of the connector. Resistance should be 3-4 ohms. If resistance is not as specified, replace fuel pump with new unit, Part No. 6472311. To further check the system, remove the assembly from fuel tank and measure the resistance of the RFI filter and pump assembly individually. Resistance of the RFI filter should be infinity. If resistance is not as specified, replace filter with new unit, Part No. 6472779. Resistance values for the pump assembly should be as stated above. *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 89-T-36, dated 3/89 In order to eliminate the possibility of damage or diminishing longevity of a service replacement fuel pump, it is always necessary to replace the fuel strainer at the same time as replacing of fuel pump. *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 86-B-110, dated 8/86 Coupled hose assemblies are not to be repaired. If a hose is damaged, it must be replaced as an assembly. Uncoupled fuel lines (3/8" fuel feed - 5/16" return line) that must be replaced have to be made of a Fluroelastomer material instead of a neoprene hose. If a clamped line is opened for service, it must be reassembled with the same type and number of clamps. Stainless steel screw band hose clamps are used on hose/pipe connections which do not have coupler fittings. Do not use copper or aluminum tubing to replace steel tubing. Do not use rubber hose within 4" of the exhaust system or within 10" of the catalytic converter. In repairable areas, cut a piece of fuel hose 4" longer than the portion of the line removed. If more than 6" inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 10". Cut ends of pipe remaining on car square with a tube cutter. Using the first step of a double flaring tool, form a bead on both ends of the pipe sections. If a pipe is to corroded to withstand bead operation without damage, the pipe should be replaced. If a new pipe is used, form a bead on both ends of it also. Pipes must be properly secured to the frame to prevent chafing. Alt. method if replacing the entire unit. REMOVAL Disconnect the negative battery cable. Raise vehicle. Remove fuel tank. Refer toFUEL TANK ASSEMBLY . Remove pump and sending unit assembly by turning the cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. Pull the fuel pump up into the attaching hose while pulling outward from the bottom support. Do not damage the rubber insulator or the strainer. INSPECTION Inspect the fuel pump attaching hose for signs of deterioration. Inspect the rubber sound insulation at the bottom of the pump for deterioration. INSTALLATION Install pump assembly into the attaching hose. NOTE: Care should be taken not to fold over or twist the strainer, when installing the sending unit as this will restrict fuel flow. Install sending unit and fuel pump assembly into the fuel tank. (Always use a new O-ring seal). Install the cam lock assembly. Turn the cam lock clockwise to lock it. Install fuel tank assembly. Connect the negative battery cable. START vehicle and check for fuel leaks.