Fuel Pump Replacement


By: RollinSlow84

In an effort to rebuild the Forum post crash, here is my contribution. A step by step how to remove and re-place a fuel pump. The maintenance was performed on a 1996 Caprice wagon. Basically all of the B/D tanks mount the same, just different filler neck and ventline location.

First off you'll want to raise the rear of the vehicle a good amount. The rear wheels of the Wagon were about 3" off the ground, this was just enough for me to use my transmission jack to keep the tank mounted on it and slide it out. You're results may vary. Safety note: chock the front wheels or put something in front to keep the car from rolling forward.

Here is the filler neck and vent line connection. There two hose clamps on the filler neck, and one on the vent line. Loosen both on the filler neck so you twist the rubber hose to help free it off the tank mount. When the tank mount end comes loose, tighten back up the other end.

These are the tank strap mount bolts, They are 13mm and a pain to get back in place. Loosen and remove the nut, but leave the bolts in place for now. Take the cross strap nut off and push the tank strap out of the way.

Now position a floor jack or transmission jack underneath the tank to support it. I used a floor jack with a piece of wood cut to fit in between the tank straps to help balance it. Put some pressure on the tank to take the load off the bolts for the straps. The bolts should come out with little effort.

Lower the tank a little bit and slide the jack towards the rear as you lower to keep the tank balanced. Remove the hose connection at the filler neck and cover up the port to prevent a fuel leak. I used two Ziploc bags and safety wire. Worked pretty good, the tank tipped over and didnt get much of leak.

Now get under the car and disconnect the the retainer for the fuel supply/return and evap lines. Its directly above the rear end.

Now I tried to cheat but it didn't work out, I tried to remove the fuelpump and sender assembly without fully dropping the tank. Don't bother you'll waste your time.

You will need a fuel line disconnect tool, I have a cheap Lisle set I bought from Sears. You need these tools!

With the tank lowered a bit you have easier access to the fuel supply and return lines. Move the rubber boot out the way and you'll see the QD. Use the disconnect tools. Select the appropriately sized one and with the sleeve facing up into the connection push it in. You might have to puch the line a little to get it in. It should slide in and then pull the lines apart. If its taking a lot of effort, stop your no fully ***-engaging the QD.

Now you're ready to drop the tank and pull it out so you can work on it. Don't forget to disconnect the wiring harness from the retainers on the body. Once the tank is out you should clean the area above it before removing the retaining ring for the fuel pump and sender assembly. The retainer is held in place with Six 10mm nuts. Pull out the fuelpump and sender assembly.


Remove the wiring and Take the cap off of the fuel pump housing, there a few tabs. Be careful when pulling out the purple wire, it has a tight retainer and you wouldn't want to break the sender assembly. I would strongly suggest you install a new in tank harness. Compare the new one to the old one and make sure the wires are in the proper terminal location.

Slide new fuel pump into housing and reconnect the wires. Install a new strainer to keep your warranty valid.

Use the new O-ring that comes with the fuel pump and install the sender and pump assembly. Tighten the nuts in a cross over pattern. I'm not sure what the spec is but they were pretty loose when I removed them, I'd say 40" lbs. Put the tank on the jack and get it close to mounted. Connect the supply, evap and return lines and wiring harness. Time to perform an operational check. Under hood, have your fuel pressure gauge connected and some wire or terminal clips. The fuel pump "jumper" allows you energize the fuel pump by yourself from under the hood. Connect a lead to the battery + positive terminal and another to the fuel pump "jumper".

The gauge should read 45psi or better. Mine read close to fifty.

Now for the fun part, remounting the tank. The less difficult was is to completely remove the drives side strap and cross strap. Its held on with the 15mm bolt. You will need a long extension or two. Jack the tank up and get the passenger side strap bolted in. Now you will have to fight the fillerneck hose back on, feel free to beat and kick the tank into submission. Use a set of tapered punches to help align the tank strap and mount holes. Loosely mount the driver's side forward tank strap mount, this will help you install the rear bolt a little easier. When all you hardware is loosely installed, then go ahead and tighten them all up.

Let me know if I missed anything, I've had my tank in and out 2 times in the past two days.


From :defdaboss

im glad i HELP the right person! it feel good to help someone and in return they make a thread like this that will help everybody else in the future!

just to make the job cheaper i suggest this very simple and very cheap tool. it works very well and fit like a glove.

same part number and its a 3/8. available at autozone/advance auto parts. im sure other stores have them but im 100% sure these 2 stores i mention has them. i bought mine there.


From: B-Body Builder

Just a suggestion but, BEFORE you remove any of the nuts on the ring that holds the sender unit/fuel pump in the tank, Take a soft brush and loosen all the dirt and debris that collects on the top of the mounting ring and surrounding area's, then either wipe it away or use a air nozzle and blow it all off. This keeps and dirt or debris from accidently falling into the fuel tank when you remove the sender unit from the tank. Also, BEFORE you start this project, Loosen the gas cap to relieve any pressure that's in the tank.


Great post!  And while you're in there, refurbish and recalibrate the gas gauge sender. (ALSO ON THE GRAIL TECH PAGE)

From: The Fooser Guy

Great Post & Pic's. As you mentioned, this was a Wagon.

On the sedan (Imp) I find it easier to just lower the rear license plate (like you're filling the tank) and un-screw the two bolts holding the filler neck to the rear of the car. That way the tank stays capped while you lower/raise it.

I also think it's MUCH easier to leave the (2) REAR cross-strap hanger bolts alone and drop the tank by using the (2) bolts at the FRONT of the straps (I think they are 15MM), even if you have to remove the 'rock shields' (a couple of small sheet-metal screws) to get to the front bolts. It's a lot easier to push the front bolts, straps and tank straight up and tighten the bolts than to get the rear two threaded thru the frame while wrestling with the tank (there is no 'adjustment' for the rear bolts). Using the front bolts lets the tank 'hinge down' on bolts that pass thru the rear of the straps, then slide the tank forward on the floor, lift the straps up out of the way for a moment while you slide the tank out under the rear of the car. I think this also gives you a bit better access to the fuel line connections (which face the front of the tank). Reverse this to install the tank.


BY: "The Fooser Guy"

Here are some helpful notes on swapping out the fuel pump  - from when I did mine.   

  I'm 'fresh off the learning curve' on the fuel pump install so my apologies if you already know this - but I didn't at the time (and did it 'the hard way').   



  •  (One drop of gas on a hot light bulb might result in the bulb exploding - and igniting the 'recently vaporized' drop of gas... not good...)

I learned that you don't want to remove the tank by removing the (2) 'cross bolts' that hold up the rear-most ends of the tank straps.  They are a pain to get out and even worse to get back in!  I'm pretty sure the factory uses the rear tank-strap bolts as hinges, and uses the front tank-strap bolts to install the tank (unless they drop in the tank before they fit the body to the frame).



  • Raise, and securely support, the rear end of the car (D'oh!)
  • Flip your rear license plate down, open and then re-seal the gas cap (depressurize the tank) and remove the (2) 10MM bolts holding the filler neck in place (leave the gas cap on the tank - this way you can remove the tank without having to worry about sloshing gasoline all over the place.)
  • From under the drivers side, rear, of the car; un-clip the 3-wire electrical connector for the wires that go up over the top of the tank.
  • Go to the FRONT edge of the fuel tank and remove the (4) 7MM sheet metal screws from each  sheet metal 'rock shield'  (between the axle and tank) and remove the shields,
  • While you are still at the front of the tank, reach up above the 'pumpkin' and un-hook the wire 'clip' that holds the (3) fuel lines up to the body,
  • Support the tank (on a jack with a good board to spread the load out) and remove the (2) 15MM 'vertical' bolts from the FRONT ends of the tank straps (the nuts are captive) and partially lower the tank,

  •  Reach up over the  front edge of the tank and un-clip the fuel and vent lines from the top of the tank (you'll need a special  5/16" and 3/8" fuel line tool, and something to catch some gas in)
  • Let the front of the tank the rest of the way down (the straps will hinge on the rear cross-bolts), then slide the tank forward and out of the tank-strap cradle  (be careful with the filler neck/cap).  Then push the straps back up and drag the tank out from under the rear of the
  •  Un-bolt the ring on the top of the tank (10MM?) and swap out the pump (be careful not to screw up the sending unit - some wiggling is necessary, but this whole thing will come out  of the tank)
  • Make sure you note the orientation of the 'sock/strainer' on the original unit and put the new one on the same way (to re-install, put the 'sock' on a table and press the end of the pump onto the 'sock' - carefully, you only get one chance at this).
  • I made a small (aluminum) plate to cover the hole in the tank while I messed with the pump to reduce the gas fumes  - may not be necessary.
  • Reverse this to re-install the tank.




 Diagonally parked in a parallel universe.




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