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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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#78 ·
So here is the start of cutting it open. I just took some pics from above and went by the floor lips for the right place to mark and cut.

1.jpg


2.jpg


3.jpg


here is where I had to be super careful not to cut intothe lines or wires..... gotta be really good with a sawzaw, otherwise, you'll make a big oops - I used a screw driver to pry up on the metal to avoid cutting at the vunerble places

4.jpg


it was nice to get her good n clean.
Notice below, the two metal strips for the hatch plate support - cost a buck each at home depot (in the lumber fittings section) and some 1/2" self tapper screws to hold the metal sides pieces. they we the 12 long pieces

5.jpg


after dropping the cover back on, those 2 side supports were very strong. no need to screw the cover plate on, just fold the rug back and walla, piece of mind for when the fuel pump needs replaced.

6.jpg
 
#80 ·
I did mine the old fashioned way and would never do it again...about lit myself on fire. My autozone pump is working fine and the fuel gauge is just a bit finicky when totally full.

Dropping the tank is for the birds!
 
#81 ·
For those of you who also need, or want, to change your fuel tank, don't forget the anti-squeal/insulator strips. I'm not sure if there's a kit out there, but you can also use roofing paper.

This is for a '92 Astro 2WD. The part numbers or procedures may vary for your year. Be sure to do your research.

My fuel pump was absolutely SHOT.



The tank was absolutely DISGUSTING. Van was sitting for 8 years. You should've seen the amount of rust and goop in there. Not to mention the stench of 4 gallons of 8-year old fuel.



I replaced the pump and sender with a "Spectra Premium SP18B1H Fuel Hanger Assembly with Pump and Sending Unit for Chevrolet/GMC." Can be found on RockAuto or Amazon for roughly $70. With Amazon Prime there's free shipping. Although I'm guessing shipping isn't much of an issue for you mainlanders.



I also replaced the tank with a Spectra Premium GM24 Fuel Tank for Chevrolet/GMC. I got mine on Amazon for $95 with free shipping (absolutely stupendous, because shipping would've been over $100 otherwise). After checking Amazon again, it seems the price jumped up to $127. Again, don't forget the anti-squeak/insulation strips. And don't forget to take the plastic skid plate off the old tank before you toss it.



Hope this helps someone down the line.
 
#83 ·
So if this question is addressed in a different thread please don't berate me just point to the thread:
I suppose I will figure it out after I have removed my pump, but I am not to that point yet.

Has anyone installed the Delphi pump with the "upgrade"? As described on ROCKAUTO.COM:

DELPHI FG0288 {Click Info Button for Alternate/OEM Part Numbers} Module Assembly with Internal Strainer Info
w/Check Valve; Original OE design had a 2x2 connector, OE design upgraded to a 1x4 connector; A 1x4 splice kit included for vehicles with 2x2 connector

As compared to the Delphi pump of the same price described on ROCKAUTO.COM as:

DELPHI FG0127 {#19180092, 25320538} Module Assembly Info
Contains Internal Pump Strainer

They are both listed as the same price....

As long as this isn't already on another thread I think its a good topic for discussion. If know one has input I will contribute what I can after I have finished the job.
Seriously leaning towards cutting a hole in the floor. Regardless of anything else it sounds like a lot more fun to be inside the van cutting a hole than outside on the ground spilling fuel and road grime all over myself. What can possibly go wrong??
 
#84 ·
Hey Broseph, long time no hear.
YES, I have on my GEN2 van. As explained by Leeann (thank you again my friend), the old connector style (square w/ 4 contacts) was prone to failure/ shorting. So, this flat-4 configuration was introduced.
When ordering the pump, you probably want to make sure it comes with the matching pigtail wire. You will need to clip the old connector (if it hasn't already been upgraded) and solder in the new one. Don't try butt connectors or the gods will punish you. I tossed the wiring conversion I did, sorry, but hopefully yours will come with guidance. If not let us know and someone can look up the signals in the FSM.

It's not too horrible a job, just be careful with removing the fuel lines as not to snap the plastic rings or clips... or once again the gods will punish you. There are youtube videos that show how to avoid that particular calamity if you need them.

Good luck, please post up what you find.
 
#85 ·
Thanks Wimpazz! Yeah I have been off the grid here for a while, too much life, not enough Astro. I am going to go with the "cut-a-hole-in-the-floor" method since I live in Oregon and its raining and I don't have a garage. Plus that will give me a really good view of the top of the pump instead of blindly reaching over the tank while laying on my back in the gravel with fuel spilling in my face. Thanks again for the sound advice. I will post once I get around to it. Luckily I have another van, a Dodge 3500 Conversion behemoth, to rumble around in the meantime.
 
#86 ·
I see from looking through this thread that some vans have a second sheet of metal under the floor and some don't. Does anyone know if there is a way to know in advance what to expect? Depending on what's down there will affect my strategy for how to cut it open. Also, if there is a second plate under the floor, any reason to not use a grinder or metal cut-off wheel, would sparks really be an issue here?
 
#87 ·
Broseph said:
I see from looking through this thread that some vans have a second sheet of metal under the floor and some don't. Does anyone know if there is a way to know in advance what to expect?
Get under and look is the only way I can think of to know in advance of starting the actual work.
 
#88 ·
Some vans have a cover over the fuel pump, hoses and tank. My '99 does, my '02 does not. Haven't looked at the '00s tank yet.

It seems to be hit or miss, so you have to see for yourself.
 
#90 ·
I had to replace the fuel pump on my '03 just a couple weeks ago. It really wasn't all that bad...although having the lift made it a lot easier getting under the van. I followed the directions in this thread and just did things very carefully, and it all turned out fine. I used the Delphi pump, even though it was a little more expensive. It was the newer "upgraded" pump. It came with a little info sheet on what is new. The internal strainer, and I think 2 support rods instead of 3, and some other technical things that I didn't honestly pay much attention to. I did have to cut the old connector out and splice the new one in, but the pump even came with butt splices. All in all it was relatively easy...just take your time. And luckily I was able to get the van towed to a friends driveway when the pump died AND it wasn't raining when I dropped the tank, so that made the whole thing a lot smoother. And honestly I'm glad to not have a hole in my floor.

Andy
 
#95 ·
Thanks to all you kind folks. No way I could have done this without you. Can't believe I thought I was supposed to detach the wire harnesses from the fuel sender unit BEFORE dropping the tank. It was only when the tank was down that I realized there was an easy-to-access wire harness to remove!!

Also nearly cinched the wire loom between the strap and the frame -- caught it just in time and routed it properly. I would have been gutted had I got the tank back up only to short all the wires!

It took me about 12 hours -- which is what I expected since it was the first time I ever jacked up a vehicle and I don't have the most extensive tool set. Removing the ring-nut was a PITA!

Anyways -- I feel accomplished and definitely couldn't have done it without this walk-through. Glad I went AC Delco OEM -- I don't really want to do that job again any time soon!
 
#96 ·
Folks,
Being "That Guy" who researches every project to death before tackling it, along with the fact that most pics in this thread have evaporated, due to the "PeeBucket fiasco/debacle, I naturally have a few questions. The actual changing of the pump is well described and seems pretty straight forward, so my questions surround the cutting of a hole, the potential discovery of a plate and the possible ins/outs of dealing with it. The actual cutting of the hole and fashioning a suitable, cool, removable cover also seems pretty straight forward to me. Bear in mind that I have a 91, shorty cargo van, with TBI.

A) Any definitive answers, measurements and/or pics as to the proper location of a 10" X 10" hole? Most convenient would seem to be a measurement either for the center of said hole or the front, passenger side corner.
B) If a plate is found, can it be found before cutting the hole or dropping the tank?
C) Can said plate be removed without completely dropping the tank? The way it is fastened in place is not evident in the few pics left in this tread.
D) Is this plate really necessary, or can it be safely left off at the end of this job?
E) If plate is found, would it be appropriate to leave in place as a "safety net" while carefully cutting the hole and then removing it afterwards?

As a relative newbie here and to Astros in general, I hope it's OK for me to make a couple observations and/or suggestions. First, this seems like such an important topic (given it's already a sticky anyway) for fuel pump virgins, it would seem appropriate to update with either new pics or replacements of the missing pics of the important stuff. I'm fairly certain that if PeeBucket hadn't taken a poop on us all, and the missing pics were still intact, all of my above questions would likely have been already answered!

Thanks Folks,
Gene
 
#97 ·
Or, ya know, remove 4 bolts and drop the tank ;)

It's not very hard, esp if you drain the tank before. I don't see how you would throughly clean the tank without dropping it(or at least it would be more difficult).
If you really want to cut it up, there is a thread on here, I think by CC that has the measurements.
 
#98 ·
please don't cut a hole in your floor... with the right tools and a couple of extra hands you can have that tank on the ground in 30 minutes or less. In a shop with a lift I had my tank on the ground in 12 minutes.

I am just saying, your going to spend 10x more work messin around with a hole (and not in the good way) and it still might turn out the way you wanted.
 
#99 ·
x2 to Will and TNB.

This was my first real auto repair job (besides swapping an ignition coil and a few oil changes)... it took me a really long time and I made TONS of mistakes but I had the tank down in about 4 hours. If I did it again, I could have it down in 30 minutes.

The AC Delco pump should last you 100K plus miles. If it was something that needed servicing every 3K miles -- then I'd say cut the hole - but it simply isn't!

:2:
 
#100 ·
Thanks folks for the comments and pep talk! The initial impetus for cutting the floor was multi pronged:

1) It seems that most driveability and running issues point to a fuel pump issue, from reading here and other things I hear/read about fuel injected Chevy trucks. This led me to think this should be expected to be a fairly regular operation. From your comments, maybe my assumptions have been incorrect. I had been planning to replace the current pump with a higher quality AC/DELCO or Delphi pump as preventative maintenance, but maybe it's not necessary. The previous owner said it was replaced a year or so back, but I have no idea what brand was used and the tank was just a tad above empty when I bought the truck!
2) The other thing is that I constantly read that one of the best ways to ensure longevity of the pump is to keep a fair amount of fuel in the tank and given that I'm not living hand to mouth, it will likely always be over half full, so dropping it becomes more of a hassle.
3) At an old, sore and fairly broken 62 years old, working on my back, and especially the getting up and down, is not my favorite pastime! Plus there is "ALWAYS" at least one needed tool that I forgot to bring down with me!

I plan to drive this thing for most of the foreseeable future, or at least as long as I'm capable of doing gigs, playing my guitar and singing, and am simply doing all I can to minimize the efforts needed to do so!

Thanks All,
Gene
 
#101 ·
As far as #1, I would leave that pump in place unless it is currently failing you. There is no way of knowing if it's going to last you 50,000miles or 250,000 miles. The TBI systems are a pretty low pressure, ~12psi and the pumps last quite a long time.

As far as #2, I fill up when I get down to the red or the light comes on(depending on the year). So I guess I probably spend a little less than 50% of the time below 50%, has not been an issue for me. There is fuel flowing through the pump cooling it, and the return goes to a reservoir at the pump, so as long as you aren't running it completely dry constantly, the pumps are good to go.
Check out this Holly external inline fuel pump(probably made by Walbro), they even include an insulating isolator for the pump to keep it all cozy in it's mounting location. ;) Anyone want to bet it's being cooled by the fuel flowing through it?

#3, I have that problem as well, except it's always at least 2 tools that I forget to bring with me ;)
 
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