OCwrencher

ZR2 Pickup Fuel Pump Removal/Installation HOW-TO

25 posts in this topic

Knowing how much these trucks eat up fuel pumps, thought I would go through the steps of replacing one. Haven’t seen any how-to threads across the S10 forums, so I put one together.

This how-to thread will explain the basic procedures of removing the tank shield and tank from an S10 ZR2 pickup (sorry Blazers) with an afternoon and basic hand tools. I know a lot of people pull the beds off, but if you’re like me and didn’t have a couple friends around at the time, this is what you’d be doing.

 

Note: There may be slight differences in years and bed/cab style, so use these steps as guidelines when you tackle your truck. For reference, the truck displayed is a 1998 LS ZR2 S10 Regular Cab Short Bed Automatic.

 

So let’s get started….

 

Tools needed:

 

-3/8” drive ratchet

-1/4” drive ratchet

-Various 1/4” and 3/8” drive extensions (3” and 6”)

-7mm 1/4" drive socket

-5/16” 1/4" drive socket

-13mm 3/8” drive socket (swivel socket is a plus if you have it)

-15mm 3/8” drive socket (again swivel is a plus)

-13mm combination wrench (ratcheting preferably)

-15mm combination wrench (ratcheting preferably)

-Cotterpin/hook tool

-Flat blade screwdriver (#2 works good)

-Battery powered impact driver is always convenient

-Magnet incase you drop a bolt inside the frame rail (ZR2’s frame is completely boxed)

-Creeper

-Floor jack and a couple blocks of wood

-Jackstands or ramps

 

27.JPG

 

1. Jack up the rear of the truck and put it on jackstands or drive the rear tires up on ramps, positioning the ramp portion towards the rear. I prefer ramps because it keeps the jackstands out of your way. Rear drive shaft removal isn’t necessary but makes it easier to remove the tank shield. That’s up to you.

 

2. Open the fuel door, locate these three 7mm screws and remove.

 

1.JPG

 

3. Crawl underneath and locate the filler neck connection. Loosen these two hose clamps which are 5/16”. Your ¼” ratchet is used here because of the tight work area. Also locate and remove the one 13mm ground strap bolt.

 

Use your cotter pin/hook tool and loosen the filler neck hoses. Wiggle and push the filler neck down into the hoses as far as it will go and slide the top of the filler neck out of the gas door surround. Then you can position the top of the neck to the rear side of the surround and pull the filler neck out of the hoses. Set it aside.

 

2.JPG

 

4. On the front of the tank, locate these points. Remove the two 13mm bolts holding the tank shield to the support bracket and the rod. Loosen the 13mm bolt on the other end of the rod and swing it out of the way.

 

4.JPG

 

5. Loosen the 13mm nut on the bottom of the shield but leave on there for now until the rest of the bolts are out.

 

5.JPG

 

6. On the top inside of the tank, locate this point on the fuel tank cross-member. Remove the two 13mm bolts and nuts.

 

6.JPG

 

7. On the outside of the tank, along the driver’s side frame rail, locate this point. Remove the two 13mm bolts.

 

7.JPG

 

8. Locate this point on the outside driver’s side frame rail, in front of the left rear most cab mount. Use your 6” extension and 3/8” ratchet to remove these two 13mm bolts. Be careful not to drop them inside the frame rail, but if you do make sure you have an extendable magnet handy.

 

After that, you can position yourself under the tank shield, prop your knee under it, and remove that nut on the bottom that you loosened earlier. If you left the drive shaft in, then wiggle the tank shield out from under the tank, move out of the way, set if down on the ground, and slide it to the passenger side of the truck. Be aware that it is heavy and awkward.

 

8.JPG

 

9. Position your floor jack and block of wood under the tank (at least a 2x6 to help spread the load and not damage your tank).

 

9.JPG

 

10. Locate this point on the outside driver’s side frame rail just behind the parking brake cable mount. Remove these 15mm bolts.

 

10.JPG

 

 

 

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11. Remove only the three bolts not shown here and leave the last bolt behind the parking brake cable (keep it pulled towards the outside of the frame rail, away from the tank so it will clear). This is where your ratchet wrench really comes in handy.

 

11.JPG

 

12. Locate this 15mm bolt on the fuel tank cross-member and remove. Droop the tank strap afterwards.

 

12.JPG

 

13. Lower the tank down slowly about 6-8”. Watch the filler neck hoses as they will interfere on the frame, so push the jack (and tank) towards the inside to help clear it. Make sure you stabilize the tank (remember you probably have fuel splashing around in there).

 

13.JPG

 

14. Locate this 15mm bolt on the other side of the tank cross-member and remove along with the tank strap.

 

14.JPG

 

15. Now you can access the top of the tank sender and disconnect the two electrical connectors by pulling the tab away from the connector and pulling it away from the sender. The tank sender connector (on the right) may have a blue tab pushed through the connector clip. Remove that first by pulling it out.

 

15.JPG

 

16. Now remove the quick-disconnect fuel and EVAP lines by pushing the two white tabs, on each line, towards the inside while pulling the quick-disconnect away from the sender. The hook tool works great to easily access the bottom sides of these.

 

16.JPG

 

17. Here you can see the tabs that need to be pushed in more clearly.

 

17.JPG

 

18. Now you can lower the tank slowly, while keeping it stable, and roll it out from under the truck. Depending on the type/profile of the floor jack you’re using, you might have to remove the blocks of wood from in between them, once on the ground, to clear your frame rail when rolling it out from under the truck.

 

18.JPG

 

19. Use a flat blade screwdriver and pry the sender snap-ring inwards to clear the retainers. You can also use a pair of big snap-ring pliers, if you have them. You also might need to spray the ring with PB Blaster or similar because it may be pretty rusty. Also, before you do any of the previous steps, clean the top of the sending unit and remove all debris that might fall into the tank.

 

20.JPG

 

20. Once the snap-ring is removed, the sending unit should ‘pop’ up because it’s under spring pressure. If it doesn’t you may need to lightly pry up on the edges of it to loosen it. If you’re replacing the pump alone and not the whole sending unit, be careful not to damage it. I recommend greasing up this ring along with the area it rests in to prevent future corrosion damage and ease of removal, if you had to get back in there for some reason.

 

21.JPG

 

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21. Pull the sender out slowly and be sure to watch out for the fuel level sender float. You will have to tilt the sending unit to negotiate it out without damaging/bending the float arm.

 

22.JPG

 

22. For reference, here is the difference between the Pickup sending unit (left) and the Blazer unit (right). Notice the difference in fuel level floats also.

 

23.JPG

 

23. If your fuel level gauge is on the fritz or just doesn’t work, here’s why. These contacts wear over time and lose connectivity. You can remove the rotating (black) piece and bend these contacts down a little to fix it. This is the Pickup fuel level sending unit (the Blazer is different).

 

24.JPG

 

24. This is the Blazer fuel level sending unit. Same principle, but a little different application. If your gauge is giving you problems, check this out and you can also bend the float contact arm upwards to achieve better connectivity.

 

25.JPG

 

After all that, you can get your new fuel pump assembly out of the box and re-install everything in the reverse order. I recommend hand threading all the bolts for the tank shield in first before tightening any of them, and don’t forget to re-attach the filler neck ground strap.

 

Good luck and have fun doing yours.

 

So there it is. If you guys have any suggestions or additions, let me know and I’ll add them to it.

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Do you need to release the pressure in the fuel system? I've had some dumb-luck doing pumps on fords. Safety glasses :thumbup:

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wouldnt it just be easier to loosen the bed bolts and lift the bed up just far enough to access the fuel tank? or no?

 

 

 

either way nice write up

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Much easier to lift the bed, imo. This method does work though, obviously.

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I've done it both ways....lifted the bed twice. I'd MUCH rather lift the bed. First time lifting the bed was a learning experience and took what seemed like forever. 2nd time around took me like an hr by myself w/ a come-along tied to the rafters in the shop. Great success that way if you're alone.

 

Regardless, this is a very nice write up. When I changed my first pump 15 yrs ago this would have REALLY come in handy! But there wasn't much info on the internet back then and there sure wasn't a ZR2USA forum. LOL!

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Yep I would say lifting the bed is easier, but for guys with a bad back and no friends around. This is easier. Plus when I did mine I had to solder an OE connector back in because the previous owner had an Airtex pump in it and wanted the tank out of the way. Thought I would put it up there for whoever to reference it later.

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:clap:

 

Very, Very Nice!

 

Sticky?

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Thank you. I am also going to do a write-up on replacing the pump itself and in-tank filters with the AC Delco kit available on eBay.

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wouldnt it just be easier to loosen the bed bolts and lift the bed up just far enough to access the fuel tank? or no?

 

 

 

either way nice write up

 

 

I can have the fuel pump in 10-15 minutes lifting the bed, hell just lifting the front of the bed like a dump truck.

 

Here was my writeup of lifting the bed

 

http://www.zr2usa.com/mboard/index.php?showtopic=48124

 

Here is teh ebay/ac delco fuel pump thread i wrote

http://www.zr2usa.com/mboard/index.php?sho...t=0&start=0

 

 

Edited by bubba68ss

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Yes, lifting the bed is the most popular way but this is the way GM says to do it. I don't feel comfortable hanging out under my bed propped up on a 2x4. Kutos to those who do, just not my cup of tea.

 

And the pump write-up I'm doing is just like the one I just did going step by step with tons of pics for the less experienced crowd, so they can do it themselves and save some $.

 

Thanks for the info and links.

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Thank you. I am also going to do a write-up on replacing the pump itself and in-tank filters with the AC Delco kit available on eBay.

 

Nice job! Thanks for doing that.

 

I have had a few fuel pumps leave me stranded on the side of the road far from home. Its nice to know what tools to carry and be prepared when your on a long trip.

Edited by Bobbing

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so question for all, mine is a replacement AC Delco and it whines really loud when i get below 1/2 tank. It has done it since I replaced it. Do you guys have the same problem? My old one did it but not as bad.

Edited by ZR2MudSlinger

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My old pump was a delco unit and it was loud, still works actually.

Edited by rustyg

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When I replaced mine, the new Delco pump was SILENT. I actually freaked when I first keyed it on after the replacement, because I couldn't hear it. When I cranked & it started, I was pleasantly surprised.

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to everyone that has a replacement pump that still whines, did you replace the fuel filter and did the replacement unit come with the new style connector that had to be wired in?

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Yes and yes, the SPI pump I installed is pretty quiet but the Delco one I removed was LOUD. I bought a case of filters to have, since I have 3 blazers to maintain. :lol:

Edited by rustyg

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Yes and yes again. Both wined and I have replace the fuel filter. I don't care bc it works awesome.

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My pump is louder than the old one but it was an Airtex that came out from the previous owner. And my new pump came with the connector to wire in but the OE sending unit's harness plugged right up to the new AC Delco pump (I picked up a used sending unit from a member to replace the Airtex). I happened to replace my in-line fuel filter just before my pump shit out.

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This post should be STICKIED! :oneofgistysfavoritesmilies:

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my blazer fuel pump looks more like the pick up style pump either they changed it later on in the years or someone else did before me.

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Great Write Up! :thumbup:

 

 

:clap:

 

 

 

Going to make this a sticky!

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Great Write Up! :thumbup:

 

 

:clap:

 

 

 

Going to make this a sticky!

 

Thanks, cool that's great.

 

This is also good info for guys like me who have full toolboxes in the bed and this is easier than unloading it ;) and guys who have toppers on the bed.

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Much easier to lift the bed, imo. This method does work though, obviously.

YES!

I just un-bolted it and had the neighbor come over and help me prop some 6x6's under it. Took about about two hours from start to finish, ON THANKSGIVING DAY!

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