How do you replace the fuel pump located on a 2000 Buick Century?

Answer 1

Late model fuel systems are typically "pressurized" systems that keep the injector fuel racks under a constant pressure.., This is accomplished by an electric fuel pump which (believe it or not) is immersed inside the FUEL TANK!!! On most models up until 1997, the fuel tank had to be removed to get at the fuel pump.... an expensive and DANGEROUS job costing anwhere from 300 to 600 bucks depending on the condition of the fuel lines, tank etc. Later models 1997 and on have and access panel under the carpeting in the trunk that allows you to gain access to the lock ring for the fuel pump. Be WARNED!! if you are a DIYer. MAKE SURE that the tank is as empty as possible; the area is well ventilated and you use tools that don't make sparks i.e rubber mallets etc otherwise you may be completing your repair on the moon while playing a harp...good luck..RONCO PS.... it is not uncommon for these pumps to get quite noisy with age ( the unexplained "whinning" you hear from the rear of the car while driving..... the noise does not mean that failure is imminent...some cars run for years with this condition I changed this pump/sending unit today on my 1999 Century. There is a small panel on the floor of the trunk between the spare tire and rear seat. Remove the rear seat and seat back. Pull up the sound deadening material and secure it out of your way. Push the trunk carpeting into the trunk area to reveal the fuel pump access panel. Remove the nuts that hold the panel. Pry up the panel and remove it. Now you have access to the pump module. (This would be a good time to vacuum off the top of the tank and defective module) There are 2 electrical connections to be removed. One of them is a normal push on weather tight connection and the other has a security pin to pull out before you can disconnect it. Push both plugs out of the way under the edge of the opening. Now is the messy part. NO SMOKING OR OPEN FLAMES FROM HERE ON...PLEASE DO THIS OUTSIDE. Remove the gas cap. The fuel lines are under pressure but less than one cup will spill out when you remove the one closest to the rear of the car. (I don't know where the pressure relief is on this car) There is a special tool for removing the (3) quick connectors on top of the fuel tank. I used a small screwdriver to depress white plastic locks on the front and rear connectors. Once they were unlocked I covered them with a rag and moved them to the left to relieve the pressure but not entirely off the neck of the connection. The middle connector is different. Either squeeze the sides or pull the top up and the bottom down to unlock it. Now you have the electrical and fuel lines disconnected. Remove the metal locking ring that holds the unit against the fuel tank by flexing it toward the center so that you can allow it to jump over the retaining channel on the fuel tank. When the retaining ring is removed you may see the fuel pump module jump upward out of the tank so keep you hand over it to control the expansion. Lift the module out of the fuel tank and be careful because it holds gasoline in the lower cup shaped area. I was able to tilt the unit to pour out some of the gasoline back into the tank before I handed it to a helper standing behind the car. The hardest part about installing the new pump was the new sealing ring underneath the flange on the pump module. It helped to use white grease on the sealing ring and tank opening to help the module to seat completely before reinstalling the retaining ring. There is also a positioning tab that lines up with a space on top of the tank to help you rotate the assembly to the correct position. I also lubricated the fuel line connectors internally with the same grease to help them slide back on the modules male connectors. After you have reinstalled the fuel lines, gas cap and electrical connectors, have a helper to turn on the ignition to energize the pump and check for leaks where you reinstalled the fuel line quick connectors. If you don't see any leaks then start the engine and check for leaks again. Replace the access panel and restore the trunk area to the original configuration. (I was able to complete this repair in an hour) GM dealer wanted $423 for the pump module but I found a new one on Ebay for $118. NOTE: the sending unit can be replaced alone but it is just as much work as changing out the complete module (and you get a NEW pump).