Chrysler RAM50/D50/Arrow 1979-1993 Repair Guide

Fuel Filter

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See Figure 1

There are three types of fuel filters:



Carbureted engines use a conventional, inline fuel filter with ordinary clamps and lines.
 
Fuel injected engines use a special, high pressure filter with banjo fittings. Note that the pressure in the system must be relieved before attempting to remove the filter in this type of system.
 
The diesel engine uses a filter assembly that not only filters sediment and water from the fuel but also, under certain conditions, warms the fuel to prevent fuel line blockage. The filter housing is equipped with a water level sensor which will illuminate a dash light, warning the operator that the level of trapped water within the filter has risen to capacity. The filter then needs to be drained as soon as possible, after the dash light has illuminated.
 

The fuel filter must be replaced at least every five years or 50,000 miles (80,000 km). This is a maximum replacement period. However, since the amount of dirt and, in the case of a diesel engine, water in the fuel varies greatly, the filter should be replaced whenever you suspect it to be clogged. Typically, the symptoms of a clogged filter are a lack of engine performance under full throttle conditions, especially at high rpm, even though the engine operates normally under moderate driving conditions. With severe clogging, the filter may cause poor running under virtually every operating condition but idle. One way to check out the filter is to follow the steps below for removal and then drain the contents out of the filter through the inlet. Drain the filter into an aluminum can. While it is normal for a light concentration of particles or a few drops of water to be trapped in the fuel on the inlet side of the filter, large amounts of water and heavy concentrations of dirt indicate dirty fuel and, probably, a clogged filter. If you find a great deal of dirt trapped in the filter, it is a good idea not only to replace the filter, but to have the fuel tank drained or pumped out as well.



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Fig. Fig. 1: Fuel filters on carbureted vehicles are secured by hose clamps, while the filters on fuel injected vehicles use banjo fittings

REMOVAL & INSTALLATION



Carbureted Engines

See Figures 2, 3, 4 and 5

To locate the inline filter, follow the fuel line back from the carburetor. Inline filters are often mounted to the frame rail underneath the vehicle. It may be necessary to raise and safely support the vehicle using jackstands in order to access the filter.

  1. Disconnect the negative battery cable.
  2.  
  3. Either use a pair of pliers to force the clamps on the fuel lines open, or use a screwdriver to loosen the screw type hose clamps, depending on the type of clamps securing the fuel filter hoses to the filter. Back them well away from the connections.
  4.  
  5. Remove the filter from its mounting clip.
  6.  
  7. Work the fuel lines off the filter connections. If they are difficult to remove, it may help to pull them off with a twisting motion.
  8.  



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Fig. Fig. 2: Inline filters are often mounted to the frame rail near the rear of the vehicle



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Fig. Fig. 3: Remove the filter from the retaining clamp



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Fig. Fig. 4: Loosen the hose clamps, then slip the lines off the filter



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Fig. Fig. 5: When connecting the fuel lines to the filter, make sure the fuel lines are installed far enough onto the connections. The line should overlap the connection about 1 inch (25mm)

  1. Inspect the fuel lines for cracks or breaks and replace them if necessary.
  2.  

To Install:
  1. Install the new filter in the same position the old one was in the clamp.
  2.  
  3. Connect the inlet fuel line to the inlet fitting on the bottom of the filter.
  4.  
  5. Connect the outlet to the outlet fitting on top. Make sure the hoses are fully installed over the bulged-out portions of the fittings.
  6.  
  7. Use either pliers or a screwdriver, depending on the type of hose clamps, to fasten the hose clamps over the filter fittings so they are beyond the bulged-out sections of the fittings, but a small distance away from the ends of the hoses.
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Start the engine and inspect the hose connections for fuel leaks. Correct any fuel leak immediately.
  12.  

Fuel Injected Engines See Figure 6

  1. First, you MUST reduce the pressure in the fuel system; refer to Fuel System for this procedure.
  2.  
  3. Unfasten the negative battery cable from the battery.
  4.  



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Fig. Fig. 6: Hold the filter with an open-ended wrench, then remove the bolt retaining the fuel hose with a box wrench

  1. Remove the air cleaner assembly; refer to the air cleaner filter removal procedure described earlier in this section.
  2.  
  3. Using an open-end wrench to hold the fuel filter stationary, loosen the bolt for the banjo type connector on top of the fuel filter with a box wrench. Perform the same procedure to the inlet connector on the bottom of the filter.
  4.  
  5. Remove the bolt or nuts attaching the filter to the bracket and remove it.
  6.  

To install:
  1. To install the new filter, reverse the above procedure. A torque wrench is recommended to tighten the bolts for the fuel line banjo fittings. If the banjo fitting washers are damaged, replace them. Tighten the outlet fitting to 18-25 ft. lbs. (24-34 Nm) and the inlet fitting to 25 ft. lbs. (34 Nm).
  2.  
  3. Reconnect the negative battery cable, then start the engine and check for leaks.
  4.  

Diesel Engines See Figures 7, 8, 9 and 10

The fuel filter element (cartridge) is contained within the filter canister which must be removed to gain access. The filter canister is located in the engine compartment and is positioned between the fuel tank and the feed pump in the fuel system.

  1. Label and unplug all electrical connectors running to the filter canister. These connectors are for the water level sensor, the fuel heater and the fuel temperature sensor.
  2.  
  3. Carefully unfasten the fuel hoses at the fuel filter. Have a supply of rags handy to catch overflow from the hoses.
  4.  

While not as flammable as gasoline, diesel fuel is slippery, smelly and very capable of staining anything it touches. Prevent spillage whenever possible and mop up spilled fluid immediately. Cat litter or similar products are ideal for dealing with puddles on the floor.

  1. Remove the two bolts holding the filter to the body and remove the filter canister.
  2.  
  3. Remove the protector and bracket from the canister.
  4.  
  5. Screw the filter out of the canister body by hand. Carefully remove the water level sensor and the drain plug from the cartridge. It may be handy to lightly clamp the unit in a vise to aid removal, but do not damage the sensor or the housing.
  6.  

To install:
  1. It is possible to clean the filter element with kerosene. However, replacement with a new cartridge is highly recommended instead of cleaning.
  2.  
  3. Install the drain plug and the water level sensor on the new cartridge. Tighten the drain plug to 3 ft. lbs. (4 Nm) and the water sensor to 9 ft. lbs. (12 Nm).
  4.  
  5. Screw the cartridge onto the body. Install the protector and bracket.
  6.  
  7. Install filter assembly onto the vehicle. Install the main fuel hoses. When tightening the clamps, make sure the heads of the clamp bolts face away from the body of the filter.
  8.  
  9. Whenever the fuel supply has run out or the lines have been opened, the system must be bled to eliminate air. The air bleed plug projects at an angle from the top of the filter housing.
    1. Loosen it.
    2.  
    3. Have rags handy and place some under the bleed port; as fuel will come out of the bleed port.
    4.  
    5. The knob for the hand pump is located on the side of the filter body. Unscrew it and pull the pump lever out of the housing.
    6.  

  10.  



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Fig. Fig. 7: Cross-section of the diesel fuel filter



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Fig. Fig. 8: Lightly clamp the diesel fuel filter unit, then remove the water level sensor and plug from the filter



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Fig. Fig. 9: Correct clamp positioning is important



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Fig. Fig. 10: Location of the air bleed port (upper) and hand pump (lower) for bleeding the diesel fuel system

  1. Work the hand pump and watch the fuel coming out of the air bleed plug; when there are no air bubbles mixed with the fuel, tighten the air bleed plug.
  2.  
  3. Continue pumping until the operation of the pump lever feels stiff or heavy during each stroke.
  4.  
  5. Push the pump lever all the way in and turn it to the right to lock it in place.
  6.  

  1. Refasten the wiring connectors to the pump housing terminals. Make certain each is firmly seated.
  2.  

DRAINING THE FUEL FILTER



See Figure 11

This applies the diesel engines only.

When water accumulates in the fuel filter, the fuel-water separator light will come on. This indicates that the filter has reached its safe capacity and must be drained. Even if the light has not come on, the wise owner will drain the filter with every oil change. This simple procedure can be done with the filter on the vehicle and can prevent severe engine damage or failure.

  1. Use the proper sized wrench to loosen the drain plug on the bottom of the fuel filter.
  2.  
  3. The knob for the hand pump is located on the side of the filter body. Unscrew it and pull the pump lever out of the housing.
  4.  



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Fig. Fig. 11: Draining water from the diesel fuel filter

  1. Pump the hand pump until the water is expelled and fuel is being pumped out.
  2.  
  3. Push the pump lever all the way in and turn it to the right to lock it in place.
  4.  

 
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