Chrysler Full-Size Trucks 1967-1988 Repair Guide

Electric Fuel Pump

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See Figure 1

The TBI system uses an electric fuel pump mounted in the fuel tank. The fuel pump used in this system is a positive displacement, roller vane immersible pump with a permanent magnet electric motor. The fuel is drawn in through a filter sock and pushed through the electric motor to the outlet. The pump contains two check valves. One valve is used to relieve internal fuel pump pressure and regulate maximum pump output. The other check valve, located near the pump outlet, restricts fuel movement in either direction when the pump is not operational. Voltage to operate the pump is supplied through the Auto Shutdown Relay (ASD).



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Fig. Fig. 1: 1988 Electric fuel pump

REMOVAL & INSTALLATION



See Figures 2 through 8


CAUTION
Perform the fuel pressure release procedure described previously in this section.

  1. Properly relieve the fuel system pressure and disconnect the negative battery cable.
  2.  
  3. Remove the fuel tank from the truck.
  4.  
  5. Remove the locking ring, then lift out the fuel pump module. Tag any lines for replacement.
  6.  



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Fig. Fig. 2: To disconnect the fuel pump line, press in designated areas



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Fig. Fig. 3: After removing the fuel tank and fuel pump module, tag the lines going into the pump

  1. Remove the sending unit attaching screws from the mounting bracket located on the drain tube.
  2.  



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Fig. Fig. 4: Unfasten the sending unit screws, then remove the bracket

  1. Disconnect the wires from the sending unit, then remove the sending unit.
  2.  



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Fig. Fig. 5: Before removing the sender, disconnect the wires leading to sending unit

  1. Remove the drain tube from the mounting lug at the bottom of the reservoir.
  2.  



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Fig. Fig. 6: After removing the sending unit, the drain tube must be removed from the mounting lugs.

  1. Remove the lower-most coil of the drain tube from the mounting lugs on top of the reservoir. Be careful to avoid unsnapping the return line check valve cover from the bottom of the reservoir.
  2.  
  3. Release the pump mounting bracket from the reservoir. Press the bracket with both thumbs toward the center of the reservoir.
  4.  



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Fig. Fig. 7: The pump bracket should slide from the slot

  1. Remove the pump mounting bracket and rubber collar from the hose. Cut the hose clamp on the supply line and discard the clamp. Remove the pump/filter assembly. Pry the filter from the pump.
  2.  



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Fig. Fig. 8: Pry the filter off, and replace with a new one

To install:
  1. Press a new filter onto the pump.
  2.  
  3. Using a new clamp, attach the supply hose.
  4.  
  5. Position the pump mounting bracket and rubber collar on the supply hose between the bulge in the hose and the pump.
  6.  
  7. Position the pump in the reservoir so that the filter aligns with the cavity in the reservoir.
  8.  
  9. Snap the pump bracket into the reservoir.
  10.  
  11. Position the coil tube on the reservoir so that the drain tube aligns with the mounting lugs on the reservoir.
  12.  
  13. Snap the lower-most coil into the mounting lugs on top of the reservoir.
  14.  
  15. Snap the drain tube into the lugs on the bottom of the reservoir.
  16.  
  17. Connect the wires to the sending unit.
  18.  
  19. Align the index tab on the level unit with the index hole in the mounting bracket.
  20.  
  21. Install the level unit screws.
  22.  
  23. Install the assembly in the tank.
  24.  

 
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