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How to change your fuel pump.

92893 Views 131 Replies 69 Participants Last post by  JesusOnSkates
This write up was done while I removed and installed my new fuel pump.

Step 1. Disconnect the negative (-) battery cable.

Step 2. Raise and SAFELY support your van with either jack stands or ramps. The higher the better, also note that it does help to raise both the front and the rear of the van.

Step 3. I reccomend that you drain the fuel from the tank unless you have a quarter or less. This can be accomplished with a hand siphon or pump.

Step 4. Remove the splash gaurd from the driveshaft side of the fuel tank. It is installed with four press in clips and multiple slip on clips. It looks like this.
Step 5. You will need to loosen the fill hose attached on the drivers side of the tank. There are two clamps on this hose. It looks like this.
Step 6. It makes it easier to disconnect the fill hose if you remove the retaining screws that hold the fill hose in place inside the fuel door.
Step 7. Break loose but DO NOT remove the drivers side retaining strap bolts, on most vans the bolts do not need to be loosened as they are set from the factory to allow the strap to rotate freely once the bolts on the opposite side are removed, mine were over tightened by the previous owner or their mechanic. There is a hidden 15 mm nut on top of the strap where it attaches to the chassis. I have a needle nose vise grip on it in this pic to show where it is. I used a 12" extension and 15mm socket and a 15mm wrench to loosen these.
Step 8. Break loose the driveshaft side retaining strap bolts but dont remove them yet.
Step 9. Now is the time to support the fuel tank. I reccomend the use of either a transmission jack or a atv/motorcycle jack for this as it greatly eases the process.

Step 10. The fuel lines and the vent lines should now be removed from the hard lines. the two fuel lines require the use of a 5/8 line wrench and a 3/4 line wrench. the two vents are simple pinch clamps that can be removed with a pliers. Removing the rubber lines for the vents is a bit easier if the tank is lowered a few inches.

Step 11. Now it's time to remove the wiring harness. The wires run across the top of the tank and over to the drivers side they then follow the "frame" rail forwards and are attached to the body near the transmission. Unplug the harness and remove it from its retaining clips. Once it is free from the clips feed it through the hole in the "frame" and set it off to the side.

Step 12. Remove only the driveshaft side strap retaining bolts and then turn the straps 180 degrees out of the way.

Step 13. Now slowly lower the fuel tank being careful to make sure nothing gets caught and causes the tank to fall.

Step 14. Now it is time to remove the fuel pump / sending unit assembly. I accomplished this with a brass drift punch. Use the punch and a hammer to rotate the lock ring counter clock wise until it lines up with the notches in the top of the tank.

Step 15. Next you will need to remove the assembly from the tank be careful with this so the strainer does not fall off in the tank and the float arm does not get damaged.

Step 16. To remove the fuel pump from the sending unit you will need to remove the wiring harness and then push the pump up towards the top of the unit and when you have clearance tilt the fuel pump outwards and then pull down on it to remove it.

Step 17. Replace the o-ring seal on the top of the tank with a new one.
Step 18. Installation is the reverse of removal.

I hope this helps someone out there with there fuel pump job. Feel free to make comments on this post so I can make sure my details are as accurate as possible.
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guyonearth said:
It's a lot easier to just cut a hole in the floor and make a panel for it. (Assuming you don't have seats in the way)
"guyonearth" has a valid point....

I don't post a lot on this forum; however, i have used it for a lot of research on my 95 astro, including this post on how to change the fuel pump. So without further delay, here is my story:

Once upon a time (haha).... it was a long week for me (working late nights) and i was on my last call on a snowy friday night about to head home while on the phone, to the not so impressed wife due to my late nights, when the van stalled. I turned the key a couple of times and i knew exactly what was wrong... fuel pump. A great way to end my week.

So there i sat in my cold van while i waited 1.5hrs for the wife to come get me - i had a lot of time to trouble shoot. I could hear the fuel running but it sounded weak so i second guessed my first diagnosis. I had spark. The engine turned over good without any mechanical failure sound... It wasnt until the next day when i came to get the van that i had a fuel pressure tester with me and determined that the pump was weak for sure (20psi) at the motor. So i stuffed the van into a car trailer and headed home.

Getting prepared to crawl under the van to drop my tank (3/4 full of fuel) i read this post and the comment about cutting a hole in the floor got me thinking... Since it was freezing cold and very windy i figured it would be way better to work on the tank from above and inside my van. So i tossed a heater inside the van and started to prep for my "mission". Once my rear seat was out and the carpet was peeled up i did some measuring and decided where to cut the hole. I used a sawsall (recip saw) to cut the hole on 3 sides then folded up the "hatch". Then.... i turned OFF the heater (very important step) haha and started to pull the pump.

My local parts store gave me a Carter fuel pump that had a shorter body and outlet port than the one i pulled out, which concerned me but this is what i was given so i "assumed" it was good. My van has the pulsator which means i don't have the small section of hose between the pump and the steel line on the pump assembly. I pushed the pump outlet as far as i could into the pulsator and replaced the whole assembly back into the tank. The van fired up and the pressure at idle was 55psi - good.

It gets better.... 2 days later i started the van in the AM and it took a couple of cranks before it fired...hmmm...makes me think the pump isn't holding pressure because the pump was shorter and maybe started to slip out of the pulsator. The next day i'm jammin on the throttle while merging onto the highway and it started to bog down. I called my parts store and talked to the "right" person to help me and he advised me the AC DELCO fuel pump was longer in body and outlet tube, just like the one that i took out. As soon as i got off the phone wih him the van stalled again....crap! i had a feeling what it was so i jumped into the back and started to move the seat, my tools, and carpet. I opened that wonderful hatch in the floor and pulled the pump assembly up just a bit to fit my hand in and push down on the pulsator - done. Started the van and i was on my way.

Back at the parts store i had the AC Delco pump in hand and i figured it was faster to swap it in the parking lot rather than go home and return at a later date. It took me 15 minutes to swap the pumps and i was on my way again, but this time with a solid solution. Could you imagine if i had to drop the tank, a second time, on the side of the road, just to make it home only to drop it a 3rd time to swap out the pumps....Honestly i am thrilled i have an access hatch because it was the most comfortable in-tank fuel pump change i have ever done.

So the moral of the story is..... get the right fuel pump and do it right the first time.

Thanks for reading my story, hopefully it wasn't too long, and thanks for all of the great info i have found on this website.

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So when you cut your access hole did you lower the tank first? I would think a sawzall would hit the tank and lines... and possible sparks.. :eek:
I am quite delicate with the sawsall, I did not need to penetrate the steel floor more than 1/2" so if you keep the blade shallow then all is good. I thought about a grinder at first but that would throw sparks for sure. The metal blade I used on the sawsall did not spark at all but even if it did one or two times I doubt it would ever cause a fire cause the tank is still sealed at that point.

If anyone is going to attempt cutting the floor to access the fuel pump then I would strongly suggest measuring twice or even three times and cutting once.


How do you go about making the hole airtight once you finish replacing the pump?
Astari said:
I am quite delicate with the sawsall, I did not need to penetrate the steel floor more than 1/2" so if you keep the blade shallow then all is good. I thought about a grinder at first but that would throw sparks for sure. The metal blade I used on the sawsall did not spark at all but even if it did one or two times I doubt it would ever cause a fire cause the tank is still sealed at that point.

If anyone is going to attempt cutting the floor to access the fuel pump then I would strongly suggest measuring twice or even three times and cutting once.


I made a fuel pump Access hole too.
I started my hole with a power drill and a shim on the bit to only allow it to drill like a 1/4' deep to insure that i did'nt touch the tank , then i used tin snips to cut a hole around 5" by 5" , this 5" by 5" hole allows you to look in and see where it is safe to cut , once you know exactly how deep you can cut then
I finished it off cutting a 10" by 10" hole with a jigsaw and metal cutting blade for a jigsaw .
You can cut the jigsaw blade in half to limit how deep it cuts to make sure it does'nt cut into the tank.
Can we get pix of some of these access holes? :text-worthless:

I am thinking of doing the same thing....

Although, I'll have to make space for both rear seats somewhere before I can get this job started.
I have the new filter and have autozone and pepboys looking for a Delco pump for me.
Gonna use dremel to make a pilot hole then jigsaw to make my access hole.

i have broken the inlets on 2 fuel pumps and had to replace is there a way to take the hoses off without breaking the pump i have the tool but it will not fit to release the line from the pump im on y 3rd fuel pump and dnt want to break again and is there a certain order for the fuel lines on a 98 i kno the middle one stays in the middle
Great point on the hole in the floor. Someone mentioned that the body support has to be cut-is this so?

Sounds like a great time saver and great also for other uses as well. Like-ice fishing?
Well, I have earlier posts from doing my fuel pump on old '90 shorty, but now, the green '96 needs a pump.

Living in a hilly area such as I do, the fuel pumps work a little harder as the fuel drains to the back or front of the tank on the hills I climb around here.

Anyhow, I am doing my fuel pump on Tuesday, and the only concern I have about cutting an access hole for the pump, is having access to the several hose connections as well. Being one to do a 'neat' job, it would be cool to have pics or specs available.

One thing I did notice was, a Fuel Pump for a 96 is a LOT more expensive than a 90... holy crap...

Got it done in better time than the last job... Replaced the pump with a Delphi. Ordered it from Napa Auto Parts here in Powell River. Had to do it on the side of the road with the wind and rain hammering down assisted by my daughter... chilled to the bone... but hey... it was a bonding experience... and she learned something..

It must be dying time for fuel pumps.. The wife's Safari had the fuel pump go out Saturday night, what an experience driving the towed van with no was much fun holding the e-brake release with one hand, left leg hiked up to the e-brake pedal,steering with one hand, and trying to get something out of the regular brakes with the remaining foot :lol: . I thought about cutting a hole in the floor of it, like on the '99 Astro, but elected to do it right and put in a Delphi pump. For reference , I used an air hammer with a panel cutting bit on it when I did mine, and no, you don't need to cut any body supports. As for the quick connect clips, I use my fingers to pinch them in, then remove them from the metal line with a pick, re-insert them into the black holders, then they just push on to re-install.
I may need a new fuel pump and the delphi/delco seems so expensive. Is there a good reliable (cheaper) alternative?
That depends ...I have an Airtex pump on my '99, it's outlasted the OEM pump...but a lot of people seem to have bad luck with non-factory pumps.

as an edit.....proper fuel filter replacement is imperative for ANY fuel pump.
I had been experiencing poor performance issues with the van for a very long time.
sometimes the van would start beautiful, then when it warmed up, would stall.
sometimes it wouldn't idle at all for a good 20 minutes.
it would miss and sputter when you tromped on the gas under load.

I had talked to several mechanics and they were telling me fuel injectors, thermostat, etc...
every now and again the check engine light would come on, then go away, so I decided to pull the codes.
the only thing it was telling me was lean at the O2 sensor.
I said screw it! instead of nickel and diming it, lets do the worst thing first. I went with the fuel pump.
I did this in my (dirt) driveway, by myself. I had about 8 gallons of fuel in the tank, so I used my floor jack to help support that through the process.
all in all, it took me only a couple of hours and was a lot easier than I expected it to be, and holy crap.... the van runs like new now!
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Interesting reading this, not how to change the fuel pump as I've done that a few times, but more the info about the brands of fuel pump used!
I have a pressure problem, it hits 60 psi, then drops right off when the pump stops. This is a shorter bodied Carter pump!!!
We got some nice sunny wether here in the UK right now, so gonna drop the tank at the weekend, with a few beers!

Hitting 60 and dropping immediately when you shut it off could be the pump, or the pressure regulator, or some really leaky injectors.
rev_les said:
Hitting 60 and dropping immediately when you shut it off could be the pump, or the pressure regulator, or some really leaky injectors.
This was the fuel pump! I had replaced the fuel pressure reg' , and nut kit, the pressure drop off was due to the fuel running back through the pump when the pump stopped running! I guess there's some sort of non return valve in there that had stopped working.
The pump was a Carter and was less than twelve months old!!!
Now have AC Delco pump fitted and problem solved, van is running sweet!

More evidence that the only pump to put in is AC Delco/Delphi.
I have changed a bunch of these pumps on vans from a 91 to a 03 I am about to do. I have never ended up stuck on the side of the road with one. I looked for a discussion about this but didn't see one. If you bang on the bottom of the gas tank with a hammer under where the pump sits while someone turns the key the pump will usually start up again. It will normally keep running until you shut it off again. You may be able to restart the pump once this way or it may work a bunch of times. This works on most any gm car with the pump in the tank. The temptation is to keep using the car cause often after you bang the tank to get it running the pump will run normal for awhile but it is just a matter of time until it goes out completely and you can't get it to start again.
Here's a "country" method of getting the pump out without getting under the van to take down the tank.

Determine location of pump access on the top of the tank and cut a 10" square hole in the floor with an air chisel. Save the piece to reinstall later.

Remove/replace pump. Cover hole with removed piece and 100 mph tape.

Pump failure tip: If you find yourself stranded at the local mall with a failed pump you may get home by turning on the key and giving the tank a couple good hits with your hand or a board. That's how a buddy got his van home once upon a time.
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