Replacing fuel pump on 2000 mercury mystique - 2000 Mercury Mystique

The most EXCELLENT thing about the Mystique and a number of Ford products, is that the fuel tank can be accessed by taking out the back seat !!!!! Yeah, that is correct, YOU DO NOT HAVE TO DROP THE GAS TANK in order to get to the fuel pump.

Before we go further - be damn sure to disconnect the battery. You are dealing with gasoline. People have burned down garages, etc by getting careless. Also, to avoid having to drain too much fuel, drive it until the fuel is very low. I personally ended up buying some large gasoline cans, because my car would not even start and then siphoning off the fuel.

Once you have the back seat lifted up - I couldn't figure out how to do it correctly, so i bent a few things - there is a connector that attaches the fuel line to the pump, which is that silver metal housing that is held down by a metal collar. The fuel line is attached by a coupling that will release if you squeeze it between two fingers. Be careful not to break it by prying too hard, or you will have to go to the junkyard for another one. The is also an electrical connector to remove - it powers the fuel pump. Some cars have only one fuel line connecting to the housing, others have two. This is because there is a "no return" type pump and a "return" type pump. The "no return" is designed to keep constant pressure in the fuel line, without having to allow excess fuel return to the tank.

I cannot remember the manufacturer I purchased from, but the pump was like 100 to 120 bucks.

To get the metal collar off that is secures the housing to the tank is not easy (and why would you want it to be). If you want to spend the money, you can find a special tool to remove it. My technique was using flathead screw drivings to tap on the parts of the ring that stuck up and slowly get the thing to slide out. Take careful note of where the hose hooks up to the pump assembly before you remove it. Also remember how the electrical connector attached to the pump assembly.

I call it a pump assembly, because the pump sits down inside a kind of plastic basket that requires you to depress some plastic tabs in order to pop the top off.

Here is some history on the Mystique and Contour fuel pumps. I had some questions about the pump and its seal and how to install it etc. and so I finally e-mailed the pump manufacturer and then called when the tech who answered gave me his phone number. This guy was great. He had worked on the assembly line for 20 years (he was in the department that talks with auto mechanics, etc). He said that the filters used on these cars NEVER fit correctly into the baskets. That is why it seems like you they won't fit and you are having to cram them in to fit inside and then mash the top of the basket on. You think that you are doing something wrong. Nope, that is how they were designed. At one point, the plastic basket was redesigned, because the stuffed in filter was getting clogged up with grit because it couldn't full deploy and then the pump would wear out.

Well, the dealerships refitted anyone that brought their car in. I personally just managed to cram the basket back together and the pump has been working fine. I just cleaned the only fuel pump filter bag and re-used it, because the new one is bigger and harder to make it fit.

However, if you want the new basket, rather than buy it online, go down to a junkyard and find one. One way that the redesigned basket is different, is that it is slightly raised off the bottom of the fuel tank floor, so that there is better circulation of gasoline under the pump, where the fuel is pulled in.

Be nice to the little o-ring that makes the seal under the fuel pump housing, they only give you one new one. One reason I called the fuel pump tech is because the o-ring had swelled. He said that the gasoline will do that sometimes and that if I let it dry out, it would return to the right size. Well, I had cut it to make it smaller. At my request, he sent me two more O-rings. Good guy.

These O-rings want to slip out when you are resealing the tank, which is really aggravating. A suggestion on another site seemed to work. Put petroleum jelly under the O-ring and it will keep it stuck in its little groove while you tap the metal collar back in place.

Hope this helps.