GM Replace Fuel Pump

Post date: Aug 22, 2010 12:50:26 AM

DISCLAIMER:

Due to the complexity and risk & danger nature of this job, it is highly recommended to leave this job to car repair/care professionals.

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AUTHOR SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED AS A RESULT OF USING OR DISTRIBUTING INFORMATION IN THIS ARTICLE. IN NO EVENT WILL AUTHOR BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS INFORMATION, EVEN IF AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

This is a maintenance/repair to replace fuel pump and/or fuel level sending unit.

1. Start engine and locate and remove fuel pump relay in fuse box under the hood. Engine will die in a few seconds.

2. Crank engine couple more times to release pressure in the fuel system.

3. Remove battery negative. Open the fuel fill cap to relieve gas pressure.

4. Raise car with floor jack and support it using two jack stands on the drive side frame. (or if you prefer, use ramp instead). The following picture is taken from front point to rear.

5. Siphon fuel gas from gas tank so that the tank is not too heavy to remove later. I use this tool (a few bucks from Autozone or AdvanceAutoParts store)

6. I am not able to insert the siphon pipe into the tank. So what I do is to remove the fuel filler pipe (shown below).

(taken from the rear of the vehicle).

Loose both cramps (using 7mm socket), rotate, loose and remove the plastic fuel pipe from the tank. It is very tight, so make sure the right side pipe is loose from the metal pipe so that you can rotate and loose the whole plastic pipe.

Once the filler pipe is removed, I use the siphon tool and insert the pipe directly inside the tank and siphon the fuel to a gas tank.

6. Now let us remove tank from the vehicle. The first I remove the frame cross bar under the fuel tank. You can see the two fuel tank braces too in this picture. The fluid you see in this picture is WD-40 that I spray for rust proof.

The following picture taken from rear point to front.

7. Before removing both fuel tank brace bars, make sure use a piece of plywood board underneath the tank and use floor jack to support the tank.

8. Here is the closeup of the drive side fuel tank brace bar and screw (15mm) used to tighten the bar. Use socket to loose and remove the screw.

9. Here is the closeup of the passenger side (actually at about the center of the vehicle) fuel tank brace bar. You can see it is not screwed but insert and rotate 90 degree so that it can hold in place. Once the drive side brace bar is removed, you can simply release and rotate the bar to remove it from the frame. The front brace bar is easy to remove. The rear one is a little hard to remove. If it is difficult, you can simply bent the bar to get clearance.

10. Before lower the fuel tank, we need to make sure to remove a few lines.

11. Remove vent valve line. See the black line with white connector at the center of the picture below. It uses a quick connection clip. So follow the trick to remove the clip so that you can remove the line from the vent valve. This picture is taken from drive side rear corner of the vehicle.

12. Here is another angle -- picture taken from the center rear under the car. Notice the red/blue electric connector to the vent valve. Remove the electric connector. I have to remove the vent valve from the rusty metal shown in this picture to get some room to get the electric connector removed. The meta click is attached to the fuel tank. I put the vent valve aside once it is completely removed.

13. Here is another angle -- picture taken from the center rear under the car. You can clearly see the filler pipe, vent valve and line described earlier. Now look at the thinner vent line with white connector to the tank. It is quick connection clip so remove this line from tank.

14. Go to the front of the fuel tank under car. You can find two fuel line connections from the fuel tank. In the picture below, the fuel tank is on the left (or rear direction of the vehicle). The yellow label is on the right (or front direction of the vehicle). Both lines use quick connection clips (part number: 800-023). Remove both lines, and be careful of the residue gas from lines.

15. At this point, we can lower the fuel tank using floor jack slowly. We still need to remove two electric connectors. There are two connectors at the top of the tank (about center location). This picture is taken from the top of the tank when you lower the tank enough (but not too much), you will get clearance to reach to these two connectors. One connector is the main 12V power and fuel level sending unit signal and another one is the fuel tank pressure sensor/signal. study carefully how to release both connectors.

16. Now you can completely lower the fuel tank to the ground. Remove it carefully from under the car. Here is the picture of the cleaned fuel tank.

Here are the fuel line and return line.

Here are big fuel filler inlet (center) and small vent line (top)

Note the EVAP vapor canister attached to the fuel tank (the box at the center of the picture below with three line connections).

Car with the fuel tank removed. Picture taken from drive side. Notice the two electric connectors hanging from frame on the left and rear fuel tank frame brace bar hanging on the right of the picture.

17. Remove the fuel pump. (I did not take picture for removing old fuel pump. The following picture shows the new pump installed already but not the fuel line connectors. The two connectors still have the red dust caps on. )

I got this tool from eBay. It is fuel pump wrench (J-44402), but it does not fit this fuel pump. So I have to use the old trick to use a big screw driver (wrapped with tape to avoid spark) and hammer to hit the fuel pump secure ring hard to get it loose and released.

Use the hammer and screw driver (wrapped with tape) to loose and remove fuel pump tighten ring. See the following picture for the ring on the top of the fuel pump.

18. Here is the old fuel pump removed from the tank. Note the fuel level sending unit at the bottom of the fuel pump.

19. Install new fuel pump is the reverse of removal. Make sure to use a new gasket. I use a new Bosch Premium fuel pump.

Move the fuel tank under the car. Use floor jack and plywood to support the tank. Make sure to connect everything back:

- fuel line and return line (front of the tank).

- two electric connectors (top of the tank).

- filler pipe (rear of the tank)

- vent line (small) (rear of the tank just above the filler pipe)

- vent valve (make sure to connect electric connector and vent line with large white connector)

20. Raise the fuel tank and install & tight two fuel tank brace bars.

21 Install and tight frame cross bar.

22. Double-check everything and make sure all connectors are connected and secured.

23. Raise vehicle and remove jack stands.

24. Lower vehicle to the ground.

25. Fill gas if necessary.

26. Install Fuel Pump Relay to the under the hood fuse box and connect battery negative.

26. Turn on car to "On" (do not "Start" the car yet) couple of times to allow fuel pump to prime.

27. Start the car.

28. Done!

If you have any question, I am happy to answer it. Glad if I can provide some help for GM owner. Please email me at pro88.car@gmail.com.