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How to change your fuel pump.

109K views 130 replies 70 participants last post by  Zebediah III 
#1 ·
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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#6 ·
Yes, that is a good detailed write up. I would like to point out that there is no need for step 7. By removing the driveshaft side bolts, the straps will pivot 180* with no adjustments to the driver side bolts and nuts. Since the bolt is left 2" out and the nut is used to lock the bolt in place, no pressure is put between the frame and the strap base.
 
#11 ·
Everyone doing this should buy Delphi or ACDelco pumps if possible...avoid Airtex, store brands, or no-name brands on eBay. The few bucks you save will not be worth the grief when it fails. The quality control on these made-in-China replacements is very haphazard. Some of them work, some don't. I have seen too many fail within a day to several months to recommend them. I did find a Delco rebuild kit on eBay for $60 that saved me alot of money, however. Also, if you are replacing the pump itself, not the whole module, be sure to CLAMP the nylon hose on, not just heat-seat it like it was originally. Small hose clamps will fit if you are careful. The pressure on these pumps WILL push that hose right off if it is not on there tight. Don't take a chance.
 
#12 ·
guyonearth said:
Everyone doing this should buy Delphi or ACDelco pumps if possible...avoid Airtex, store brands, or no-name brands on eBay. The few bucks you save will not be worth the grief when it fails. The quality control on these made-in-China replacements is very haphazard. Some of them work, some don't. I have seen too many fail within a day to several months to recommend them. I did find a Delco rebuild kit on eBay for $60 that saved me alot of money, however. Also, if you are replacing the pump itself, not the whole module, be sure to CLAMP the nylon hose on, not just heat-seat it like it was originally. Small hose clamps will fit if you are careful. The pressure on these pumps WILL push that hose right off if it is not on there tight. Don't take a chance.
Worse yet, I've seen those cheap pumps work but not work right. My neighbor got a cheap one and the van ran, but it had an ugly miss and loss of power over 35 mph. Turns out the pump would put out 60 psi at idle but once you put a load on it, it would drop to 52-55 psi and once shut off, held no pressure at all. A new Delphi pump solved all of his problems.
 
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#13 ·
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)
That's Funny, a friend of mine suggested the exact same thing.... :D

I am doing the Fuel Pump thing today on my 90 Safari. If I run into any oddities, or something not listed, I'll pass it on.

PRDave
mar 28 2010
:cool:
 
#15 ·
Yeah, have a buddy coming over, has a floor jack, tank has only about 10 litres of fuel in it. But hey, THIS How-To will save me a LOT of time, THANK YOU !!

Have done 2 of these in-tank fuel pump changes before on my 2003 Cavalier, so at least I know what I am in for, of sorts... :)
 
#16 ·
Just remember dont take out the outboard bolts on the tank straps only the driveshaft side ones. Also try to find a flat piece of wood to place between the jack and the tank to even out the pressure on the tank just for the simple fact that you dont want to bend it up and possibly do damage to the sending unit or not be able to put the assembly back in.
 
#17 ·
Well, so far so good... Everything came off fairly easy.
Had to scrape some weatherproofing off of some hose clamps, have to replace a one of them, however went fairly good.

A Few things to note: 1990 GMC Safari - I did not have to deal with any splashguard, but most annoying, the four hoses that connect from the Sending Unit to the fixed line hookups are ABOVE the Tank. No access to unclip / loosen hose clamps until you drop the tank which actually gives you plenty of room (and I'm not a small guy) to work with. Considering where I live (BC Canada, West Coast - Plenty of Rain), for a 20 year old vehicle it was pretty clean under there.

Most odd though, Once the tank lines were disconnected, I could NOT figure out how to disconnect the power line going to the Sending Unit. Yellow Clip. 3-4 wires going into it. Anyhow, it is engineered that I was able to remove the Sending Unit / Fuel Pump assembly while this was still attached.
LOTS of extra wiring simply clipped along the frame edging to the front of the vehicle.

If anyone can tell me how this comes apart, let me know. As it may appear, I couldn't 'pull out' what appeared to be the wired insert into the Yellow Cap without doing damage. I see no release of the clip....



OK, so this clip does NOT come apart. I found images on Yahoo that shows my sending unit, and as new, it comes with the clip intact.

So if your in the same spot, do not attempt to seperate this little yellow clip from the top of the Sending Unit.
Question Answered

PRDave
Mar 28 5 pm PDT
 
#18 ·
The wiring harness runs up towards the transmission cross member then turns toward the center of the van where it is a simple plug and can be detached.. I guess they put it there so it doesnt wiggle loose or become damaged and require you to remove the tank to fix it.
 
#21 ·
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.

Dave
 
#23 ·
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.

;)

Dave
 
#25 ·
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.

;)

Dave
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.
 
#26 ·
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.

Jun
 
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