Replacing The Fuel Pump In A 97 Seville: Step-By-Step Guide

The fuel pump in a 1997 Cadillac Seville is located inside the fuel tank. The pump can be accessed by removing the rear seats or through an access panel in the trunk. Before attempting to replace the fuel pump, it is important to relieve the engine's pressure and disconnect the negative battery terminal. The fuel lines and electrical wiring should also be disconnected, and the fuel tank should be cleaned to prevent dirt from entering the hole. When installing the new pump, it is crucial to moisten the O-rings with petroleum jelly or silicone grease for a tight seal.

Check for access panel in the rear of the trunk

To check for an access panel in the rear of the trunk of your 1997 Cadillac Seville, start by looking under the carpet or mat in the trunk. If there is a hatch, it will likely be in this area, towards the front right of the trunk, just in front of the spare tire well.

If you cannot locate an access panel, it is likely that your model does not have one. According to some sources, the Cadillac Seville models from 1998 onwards have an access panel, while others state that the 2000 and newer models have this feature. Therefore, you may need to drop the fuel tank to access the pump.

Before attempting any repairs or maintenance on your vehicle, ensure you have the correct tools, safety equipment, and knowledge to perform the task. If you are unsure, consult a qualified mechanic.

Disconnect fuel lines and electrical wiring

Disconnecting the fuel lines and electrical wiring is a crucial step in changing the fuel pump of a 1997 Cadillac Seville. Here is a detailed guide on how to do this:

Firstly, make sure you have the right tools for the job. You will need an air gun, 3/4" and 5/8" line wrenches, a flathead screwdriver, 13mm sockets, needle nose pliers, brass punches/rods/tubes, a hammer, petroleum-based grease, and dielectric grease. It is also recommended to have some penetrating oil for the fittings and time if this is your first time removing the pump.

Now, locate the fuel pump relay and relieve the fuel pressure from the engine side. This will depressurize the rail, but remember that you will still have pressure from the regulator to the pump. Pull out the fuel pump relay and turn the engine off.

Next, locate the electrical connector on the pump and remove it. The bolt is a 13mm hex, and the plug just unplugs. Disconnect the wiring and set it aside.

Now, you can move on to the fuel lines. There are two lines: a small tube and a large hose. First, loosen the small clamp on the small tube using a line wrench. Then, loosen the large hose from the pump side. Be careful, as there will still be pressure behind the large line. Once it is loose, slowly remove it to avoid a shower of gasoline. Wear safety goggles or a face shield for protection.

Check that the O-rings come out of the lines, and you have successfully disconnected the fuel lines and electrical wiring from the fuel pump.

Remove lock ring and module

To remove the lock ring and module of your 1997 Cadillac Seville's fuel pump, you will first need to jack up the car and support it with jack stands. Remove any necessary shields and exhaust piping. Disconnect the fuel lines and electrical wiring, and remove the straps.

Once you have done this, lower the fuel tank using a floor jack. Clean any road debris from the top of the tank. Now, you can remove the lock ring and the module. If you are replacing the whole unit, you can install the new one at this point, but if you are only replacing the pump, you will need to remove the pump from the module.

To reinstall, simply follow the same steps in reverse.

Install new pump and reconnect fuel lines

To install the new fuel pump and reconnect the fuel lines, follow these steps:

First, check if the new pump comes with an O-ring. If it does, clean the spot where the O-ring will sit and slide it into position, moistening it with petroleum jelly. If your pump did not come with an O-ring, you can reuse the old one.

Next, put the new pump into the tank, turning it so it sits in the same way as the old pump. Put the new retainer ring on, then wet the top and bottom so that it will be easy to install. Tighten the pump into place.

Now, use petroleum jelly to wet the O-rings and fitting nuts, as well as the threads and tubing the nut slides over and pushes against. This will give you a tight seal and keep the plating on the tubes from galling.

Finally, reconnect the fuel lines and put everything else back in place. Refill the tank and start the engine to test.

If your pump is located under the car, jack up the car and support it with jack stands. Slide under the car and follow the fuel lines toward the fuel tank. Once the pump is located, bolt it into place and reconnect the fuel lines.

Test the engine

Once you have replaced the fuel pump in your 1997 Cadillac Seville, you will need to test the engine to ensure that the new pump is working correctly. Here is a step-by-step guide on how to do this:

Step 1: Locate the Fuel Pump

The fuel pump in your 1997 Cadillac Seville is located inside the fuel tank.

Step 2: Turn the Key to the "Run" Position

Turn the key in the ignition to the "run" position (just before starting the engine) and listen for any buzzing coming from the fuel pump. If you don't hear any noise, proceed to the next step.

Step 3: Set the Amperage on a Voltage Meter

Set the amperage on a voltage meter and place the clamp on the positive wire that leads to the pump.

Step 4: Start the Vehicle and Record the Amperage Reading

Start the vehicle and record the amperage reading on the voltage meter. Then, compare this reading to the manufacturer's specifications.

Step 5: Remove the Electrical Connector (If Necessary)

If the pump did not turn on at all, remove the electrical connector on the pump.

Step 6: Set DC Volts on the Meter and Place the Positive and Negative Leads

Set the meter to DC volts. Place the positive meter lead on the terminal of the positive wire in the connector and the negative meter lead on the terminal of the negative wire.

Step 7: Turn the Key to the "Run" Position and Check the Voltage Reading

Turn the key to the "run" position again. If the voltage reading is the same as the battery voltage, then the pump has failed and will need to be replaced.

Additional Notes:

• It is recommended that you ask a technician to perform the test or replacement if you are unsure about any of the steps.
• Always exercise extreme caution when working with fuel and electricity, as there is a risk of fire and electric shock.
• Ensure that you are working in a well-ventilated area when testing and replacing the fuel pump.
• Keep a fire extinguisher nearby in case of any accidents.
• If the fuel pump is not working correctly, you may need to check for blockages in the fuel lines or a faulty fuel filter.

Frequently asked questions