Saturday, July 19, 2008

Weekend Workout

We don't have to tinker under the hood nearly as often as we used to now that we all drive fuel injected cars, but we still have to pay attention to symptoms. You can still fix problems on cars today, and it will save lots of money in labor expenses. Our car is a 2000 Chevy Astro, and the first fuel pump began to fail at a little over 50,000 miles. The symptoms are pretty clear when the fuel pump is failing. The car cranks too long when you want to start, and if you turn on the key, let the fuel system pressure up, and then crank, the engine will start and run fine. I think what is happening is the foot valve leaks back when the car is at rest. When the foot valve dies completely the pump will not work, so you need to change the pump, and it is inside your gas tank.

The fuel pump lasted for over 110,000 miles this time, but it was getting progressively worse all week, so today I was under the car. Even though I have done this task three times before, I looked up instructions on the internet to see if there were any good tricks to make it easier. Here are the steps from WikiPedia, with my comments in parentheses.

0. make sure gas is almost empty, easy to handle. (Plan ahead so you have the tank below half and it will be fairly easy to handle. We had ours down to a third, and it was no problem.)

(Work outside on a paved surface. Jack up your car on the driver's side and set it securely on jack stands. Have it up high enough that the gas tank can be slid out from under the car. This will be about as high as you can jack the car with a 1 1/2 ton car jack. Plan your moves so you are not under the car until the jack stands are secure. Don't get crushed; Please.)

1. remove gas fill tube, 2 screws at cas cap and 1 bolt at frame. (Loosen the clamp holding the gas fill tube to the tank and slide the clamp out beyond the emergency brake cable.)

2. loosen 2 strap bolts, have floor jack with 1"X 6" board atop it ready under tank to support lowering about 6 inches from ground. (The tank will be very awkward to balance on top of a jack, and you have a big drop at the end of the process with this method. Make two stacks of 2" lumber scraps; one ahead of the center of the tank, and one behind. Shim this stack up close to the tank and unscrew the strap bolts. They are a good three inches long and will set the tank on your stacks of lumber. Lift one end and remove a board; repeat on the other end; etc.)

(Crawl under the car so you can look over the tank next to the driveshaft. There are three lines from the pump with retainers holding them to metal lines. Tap on them to shake out the dirt, and carefully squeeze the nylon catch, then wiggle the flexible line off of the metal line. The nylon retainers should remain on the metal line. One line does not have a separate retainer; just squeeze it and wiggle the lines apart. The first line you open may have pressure, maybe not if the pump leaked back. Be careful not to get fuel in your eyes.)

(The filler pipe has a hose affair which sticks into the tank several inches. Wrestling this out of the tank is the worst part of the job, and also is your best chance to contaminate the tank with dirt. Putting it back in at the end of the job is easy.)

3. remove 2 wire plugs, one may need to be replaced, new one in box with fuel pump. (The wire plugs are in the middle of the top of the tank, so you will remove them after the tank is down.)

4. remove fuel line, 2 have internal clamps, toss and get new ones, two diferent sizes. old will not work. (You already did this and you can re-use the retainers if your were careful.)

5. lift tank off hanger that are towards passenger side, lower with jack. (Ease the tank out, back end first after you have it on the ground. Watch your wiring in case GM was stingy. I had plenty of slack.)

6. pull out from under truck. leave in plastic protection pan.

7. remove pump , screw driver on snap ring, sides straight up. (I think they are trying to move the retaining ring by beating on it with a screwdriver. This does not work well because there is a heavy rubber ring under it that soaks up any impact. Use two sets of Vise-Grips to walk the retainer around. It is easy and less frustrating.)

(In this photo the Vise-Grip is putting the retaining ring on. Two Vise-Grips will easily walk this ring either way for you.)

(Lift out your old pump and compare it to your new one. Install the new rubber ring on top of the tank, ease in the new pump, and re-install the retaining ring.)
8.install new one. remember o-ring:-)
9.reverse process.

(Do this job in daylight and do not use a trouble light around an open gas tank. I prefer to use an LED flashlight around anything flammable. Keep smokers away.)

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