Fuel Pump/Fuel Send Sensor Replacement

[RedZ71]

so here is my wrapup on how to do a fuel pump (or in my case, just a fuel send sensor) replacement on a NBS truck. mileage may vary on a single cab truck, so make sure the middle of your gas tank is under your bed. that said, i chose the "remove the bed mehod.

(im going to post the thumbs and link them since my cammy takes them so big and i didnt bother to size them down)

First thing is to remove the 8 bolts that hold the bed down, and unplug the electrical connections for your rear lights. in the first pic, the elec connections are at the top, i put the hitch in the pic so you can see some relative location of where the conns are.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03052.jpg (http://www.z71silverado.com/2001z71/truck/dsc03052.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03054.jpg (http://www.z71silverado.com/2001z71/truck/dsc03054.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03058.jpg (http://www.z71silverado.com/2001z71/truck/dsc03058.jpg)

Next, unscrew the filler tube and disconnect it from the bed. i just pulled the screws out from around the door of the filler. there is a ground wire thats connected to the cap that you will see, but it goes to the frame, and doesnt need to come off.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03056.jpg (http://www.z71silverado.com/2001z71/truck/dsc03056.jpg)

lift off the bed and set it aside. i was planning on setting it back on the frame, with the wheel well over the bumper, but measuring the length of the part from the wheel well forward didnt look like it would sit there without damaging the bed. i also wrapped a towel around the ends of the bumper, so that if the bed were to strike the bumper as we were picking it up, it would hopefully not get all scratched up from the bumper. also, note that the best place we found to pick the bed up was where my black fender flares meet the bottom of the bed. there are some supports there that kept the bed from bending when we lifted it.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03060.jpg (http://www.z71silverado.com/2001z71/truck/dsc03060.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03063.jpg (http://www.z71silverado.com/2001z71/truck/dsc03063.jpg)

once i had the bed off, i could see that the opening was caked in mud, obviously from an offroad trip from the past. hehe. i took a couple of screwdrivers, and broke it up, and washed it away with a bucket of water.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03062.jpg (http://www.z71silverado.com/2001z71/truck/dsc03062.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03064.jpg (http://www.z71silverado.com/2001z71/truck/dsc03064.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03065.jpg (http://www.z71silverado.com/2001z71/truck/dsc03065.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03066.jpg (http://www.z71silverado.com/2001z71/truck/dsc03066.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03068.jpg (http://www.z71silverado.com/2001z71/truck/dsc03068.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03069.jpg (http://www.z71silverado.com/2001z71/truck/dsc03069.jpg)

the gold ring holds the fuel pump to the tank, and has some tabs that keep it from spinning. i had to hold a lock tab up and tap the ring loose with a screw driver and hammer. im sure you were supposed to use giant channel locks or something, but i didnt have that. getting it off was easier than getting it back on later.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03070.jpg (http://www.z71silverado.com/2001z71/truck/dsc03070.jpg)

[RedZ71]

before the pump is pulled, obviously the fuel lines have to be disconnected. they are pretty stiff, but they just squeeze and slip off. there are also a couple of electrical connections to the pump that are also to be removed.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03071.jpg (http://www.z71silverado.com/2001z71/truck/dsc03071.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03073.jpg (http://www.z71silverado.com/2001z71/truck/dsc03073.jpg)

the fuel pump will lift up and out. some of the tubes are longer and mounted on springs, so they will require a little finesse to get the whole unit out of the whole, but it will come on up pretty easy. fuel will leak out of the unit, so if your hole is dirty like mine was, be very careful not to let dirt get in there.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03075.jpg (http://www.z71silverado.com/2001z71/truck/dsc03075.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03077.jpg (http://www.z71silverado.com/2001z71/truck/dsc03077.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03078.jpg (http://www.z71silverado.com/2001z71/truck/dsc03078.jpg)

my fuel pump was covered in a thin coat of brown slime, probably mud, which there was a blob of down in the tank when i looked in there. likely it leaked in while i was submerged. i cleaned the upper lip as best as i could, but i dropped a chunk of mud in there. to get it out, i got a 3/4 hose from lowes, and just syphoned it out. REMEMBER syphoning gas by mouth and hose is dangerous, so if you didnt use to work in a toxicology lab and know how to do it without getting it in your mouth, then you likely should by a hand operated pump. dont take chances.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03090.jpg (http://www.z71silverado.com/2001z71/truck/dsc03090.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03091.jpg (http://www.z71silverado.com/2001z71/truck/dsc03091.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03092.jpg (http://www.z71silverado.com/2001z71/truck/dsc03092.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03094.jpg (http://www.z71silverado.com/2001z71/truck/dsc03094.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03104.jpg (http://www.z71silverado.com/2001z71/truck/dsc03104.jpg)

if your changing out any parts, now is the time to do it. detach your old fuel send sensor, and toss it. attach the new one cafefully, as it does feel kinda delicate. remove the old o-ring, and use the new one that comes with your sensor.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03098.jpg (http://www.z71silverado.com/2001z71/truck/dsc03098.jpg)

lower it all back into the tank. before you reattach the fuel lines, put the gold ring back over the top of the assembly. attach the lines, and press the fuel pump assembly firmly into the hole. i had to tap mine with a rubber mallet to get it down far enough for the gold ring to be able to turn under the teeth that hold it down (they are angled). replace your electrical connections, and reattach your fuel lines.
http://www.z71silverado.com/2001z71/truck/thumbs/dsc03105.jpg (http://www.z71silverado.com/2001z71/truck/dsc03105.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03111.jpg (http://www.z71silverado.com/2001z71/truck/dsc03111.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03115.jpg (http://www.z71silverado.com/2001z71/truck/dsc03115.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03116.jpg (http://www.z71silverado.com/2001z71/truck/dsc03116.jpg)http://www.z71silverado.com/2001z71/truck/thumbs/dsc03117.jpg (http://www.z71silverado.com/2001z71/truck/dsc03117.jpg)

afterwards, your computer will likely kick out some fuel errors, but mine had no problem starting on the first try, and didnt stutter at all. replacing the bed is pretty straight forward, and is the reverse of the way you take it off. i had 4 guys, each holding the bed where the end of the fender flare is, and one other guy guiding the fuel filler tube up into its place in front of the filler door. i drove mine out and filled the tank up, and the "check engine soon" light went out.

this whole job turned out to be much easier than i expected, and only took 3.5 hours from beginning to end (and that was working pretty slow).

[Luke2kZ71]

:cool: thanks aloty johnathan :D

[00silverado5.3]

Awesome thanks for the great technical article. How much did the new "fuel send sensor" set you back at the dealer?

[Luke2kZ71]

the pics are broken :bawl:

[Ryan98948]

Hey man I just did mine today (well i did some of one of my friends who works at a local dealer did the real pump changing)

He told me just to take out the bolts on the drivers side disconnect the fuel filler and loosen the bolts almost out on the pass side and jack up the bed.

Well I did that and when I did that he came over and switched out the pump for me. only took him about 15 mins to do it. It took me about an hour to do the stuff on the bed.

Total cost was 250 (his cost) for the pump-sending unit- float and a case of coronas for labor :D
If you were to buy a pump from a dealer at "customer cost" it would have cost about 430 without tax.


Just an alternative to taking off the whole bed or dropping the tank :head:

[4wheelin69]

Ryan98948

Did your truck give you any kind of warning that the pump was going out? My fuel pump starts to sound loud towards the end of the tank and am affraid it is going out, is there any signs to look for.

thanks

[Ryan98948]

Originally posted by 4wheelin69
Ryan98948

Did your truck give you any kind of warning that the pump was going out? My fuel pump starts to sound loud towards the end of the tank and am affraid it is going out, is there any signs to look for.

thanks


Nope. It just started to sputter about 2 blocks from home and then it quit right when i got to my house.
Luckily i had enough momentum for it to get up in the driveway.
Pretty convienient time to go out if you ask me :D
Also it stated up after it died but only for a couple seconds and then nothing after that .
No pressure and the pump had power to it.

[C1500 Downunder]

When I changed the pump in my '92, there was also an earth strap screwed to the leading edge of the tray to the filler tube.
Make sure this is undone also if it is there.
It had us scratching our heads for a little while as to why the tray would not lift off.

[ukellyu]

Why Do They Offer An In Line Fuel Pump For My 1999 Chevy 3500? Does It Replace The One In The Tank? How Does It Wire?

[RedZ71]

I revisited this again yesterday, it was time for a full replacement. This time around I did the angle-lift method, and it worked fine. I actually unbolted all 8 bolts, and hoisted it up by the driver side of the bed with an engine hoist. Looking back, leaving the passenger side bolts partially in as mentioned above, might have saved a little nick i gave myself at the rear right, below the gate hinge. But all in all, the whole thing was quite simple, and I could have done it even without the help of my friend who was standing by.

Oh, one other thing, the electrical connector on the pump has changed, and I had to splice on a new connector, that was included in the package (all the wire colors matched up to the factory harness on mine).

[frankly]

I revisited this again yesterday, it was time for a full replacement. This time around I did the angle-lift method, and it worked fine. I actually unbolted all 8 bolts, and hoisted it up by the driver side of the bed with an engine hoist. Looking back, leaving the passenger side bolts partially in as mentioned above, might have saved a little nick i gave myself at the rear right, below the gate hinge. But all in all, the whole thing was quite simple, and I could have done it even without the help of my friend who was standing by.

Oh, one other thing, the electrical connector on the pump has changed, and I had to splice on a new connector, that was included in the package (all the wire colors matched up to the factory harness on mine).
how high did u lift left side of bed (from bolted position) remove pump what angle did it wind up being,right side of bumpere to bed contact become an issue,thanks for taking time to reply in advance.

[RedZ71]

how high did u lift left side of bed (from bolted position) remove pump what angle did it wind up being,right side of bumpere to bed contact become an issue,thanks for taking time to reply in advance.

maybe 18 inches. i supported myself by laying over the top of the tire, and was able to reach the pump and wiring without a problem.

the contact i had with the bed to the bumper on the right rear, was due to the fact i took out all 8 bolts. if you leave all the passenger side in(back them almost all the way out), the bed should maintain proper distance to pivot upwards without a problem (i think, looks good on paper tho).

[frankly]

maybe 18 inches. i supported myself by laying over the top of the tire, and was able to reach the pump and wiring without a problem.

the contact i had with the bed to the bumper on the right rear, was due to the fact i took out all 8 bolts. if you leave all the passenger side in(back them almost all the way out), the bed should maintain proper distance to pivot upwards without a problem (i think, looks good on paper tho).
it works fine that way,i left rt. side bolts in,- bolt closes to cab,i removed that one.Made me a T-brace,removed DR.side wheel,jacked it up 20inches.An hour later I was on my way,thank's for the info.

[RedZ71]

i finally got some pics of the process:

http://www.z71silverado.com/2001z71/truck/thumbs/dscn0209.jpg (http://www.z71silverado.com/2001z71/truck/slides/dscn0209.html)
http://www.z71silverado.com/2001z71/truck/thumbs/dscn0213.jpg (http://www.z71silverado.com/2001z71/truck/slides/dscn0213.html)
http://www.z71silverado.com/2001z71/truck/thumbs/dscn0212.jpg (http://www.z71silverado.com/2001z71/truck/slides/dscn0212.html)

[sgtgat]

Hey guys is there anyone who did the tank drop I have the bet sealed to the cab for subs. thanks

[16vconversion]

there doing it the easy way , Your gonna have to drop the tank dude. same idea on the hoses/electrical for the sender but you get have dirt fall in your mouth & eyes and Pray the bolts for the straps come out !