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2006 gmc envoy_denali
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So I changed my fuel sender on my own (everyone always says you can do it with a buddy) but just here's some tips before you venture underneath your car... Please keep in mind I am not a mechanic and the extent of my vehicular repair knowledge is limited to changing my oil and thats about it.

Please note that these are just tips that I wish I had known before I attempted replacing the fuel sender on my own. This is in no way meant to be a manual in how to do it and I don't assume responsibility if anything goes wrong.

This was on a 5.3L V8 Denali, but I don't think the regular 6 cylinder Envoy's would be much different.

Tools I used:
Hammer
Screwdriver
Jack/lift
Set of ramps
5-Gallon Canister of Gas

Above all... as everyone will say, make sure your tank is as empty as possible. If you're not sure, be safe and siphon the tank. Also, make sure you disconnect the battery terminal and the fuel pump fuse.

First: Check online for the price of the fuel sender; don't go to the dealerships. I paid about $80 including shipping for mine. Be sure to ask if a new gasket for the fuel pump comes included as you will need one once you remove the fuel pump. A good tip is if you really want to be safe, look up the price difference in an entirely new fuel pump. If it's not that big of a gap, definitely replace the fuel pump all at once as it should come with a new fuel sender already attached anyways and you can save yourself A LOT of time if that's the case, especially since I've heard a lot of complaints that once the fuel sender goes out, the pump itself is not far behind.

Second: Once you get it, call a local mechanic and see how much they want to install it for you since you have the part already. My mechanic quoted me about $150-$200 for the labor (no parts would be needed) and looking back, I wish I would've taken him up on it.

Third: Those $30 (average) vehicle ramps are the easiest thing to get underneath the car. Because the tank is on the driver's SIDE (emphasis on the side) the best way to do this is to put the ramps on the driver's front and rear tire and pull a side lift; I will explain why later.

Fourth: Once you get underneath the car, it's pretty simple, just "plug and play" Unbolt the obvious two straps that hold up the tank BUT not before you do so, make sure you have something to keep the tank held in place. Personally, I used a regular jack that you typically would use to raise the car in order to change a tire. Set it under the center of the tank as high up as it'll go and once you unbolt the tank it should just rest on the jack. The tank itself is plastic and not very heavy at all when empty, but this is to keep from putting strain on any clips or fuel lines and breaking them once the straps are no longer supporting the tank.

Fifth: CAREFULLY unclip the six or seven or so fuel lines that go in and out of the tank. Use extreme caution in this step because the only thing holding the fuel lines together is a plastic horseshoe looking clip ("Fuel Line Retainer Clips") and in adverse weather conditions they maybe extremely frail and prone to breaking in half, as I learned from personal experience. Also, I was lucky in that my tank had about a little under a gallon of gas left in it when I performed the operation but still when I unclipped the two lines towards the front of the tank gasoline spilled out so be on the look-out for that as well.

Sixth: NOW, if you were as unfortunate as I was to break a few of the "Fuel Line Retainer Clips" do not fret! (If you didn't break any clips, move on to Step 7) I went through 3 dealerships and countless Advance Auto Parts and the like, trying to find replacements. No one knew what I was talking about and even the first 2 out of 3 GM dealerships tried to tell me that they were not sold separately and I would have to buy each and every fuel line in order to get replacement clips!!! :hissy: This is DEFINITELY NOT the case. Part Number 21992748 is for one size and Part Number 2271568 is for the other size. I believe there's yet another size but I misplaced that part number. In any event, if you give the dealer either part number they can find them. It cost me roughly $5 per clip which I was more than happy to pay after being convinced by 2 other GM dealerships that the only solution was to pay $100+ for EACH entire fuel line.

Seventh: At this point you should have the tank free from all straps and clips and be able to lower the tank with your jack/lift. Looking at the top of the tank you should easily be able to see the flange that holds the fuel pump to the tank. I took the hammer and the screwdriver, wrapped the screwdriver in a towel (to avoid sparks) and smacked it a couple times (REALLY HARD) until it finally gave way and the flange turned, allowing the fuel pump to be lifted out. Next, I pulled it out as much as I could, minding the existing fuel sender. Make sure you DISCARD the old rubber gasket/ring that was between the flange and the tank. Make sure you do this as soon as you can so that you can distinguish between the old and new.

Eighth: This part was probably one of the hardest. I don't know if this is across the board, but on my fuel pump it was basically two pieces. The pump itself, and a kind of bowl pice that clips on to the bottom of the pump where the fuel sender clips on to. That piece would not come out of the tank, to save my life. Maybe there's a trick to it, but I had to separate the two pieces and just replace the sender inside the tank. After this step, you're pretty much done! You just have to put back everything as you found it, with the exception of making sure you put a new gasket underneath the flange.

Ninth: Once you finally get everything back in place, and everything is bolted up, and you reconnect the battery terminal and fuel pump fuse, put a couple gallons of gas in the tank. NOW... I, (under the impression that the tank was in the back of the car) had placed the ramps under both rear tires so the rear end of the vehicle was elevated. When I put in 5 or so gallons into the tank and tried to start it up nothing worked. Me being the idiot that I was left it overnight and tried again the next day and still nothing happened. It wasn't until I lowered it off the ramps to get it ready to be towed after having called a tow truck to come pick it up (because I had enough of it) and completely leveled the car and consequently the gas inside the tank, that it started right up.

The check engine light turned off and as soon as I filled up the tank everything was back to normal!

Again, personally I don't recommend doing it yourself, but if you decide to anyways consider those tips. Hope this helps at least one person!
 

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saab
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Nice write up!

I had to replace the fuel level sender on my Wifes 06 Envoy Denali. It took me about 30 mins to swap it out. the "bowl" you speak of is usually referred to as the "bucket". the complete "module" comes out as one piece. You just have to wiggle it around and tilt it as you pull it out. Its very easy to do. Oh and those retainer clips are sold in packages of 5 at Pep-boys and other auto parts stores. there are 2 sizes, one for the return line and one for the main feed line. I always keep them around for other GM cars...
BTW, if your fuel pump ever goes out, its cheaper to just replace it with an aftermarket Walbro 255 lb/hr in-tank pump.



 

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2005 gmc envoy_denali_xl
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6 Posts
Thanks for this, it will be really helpful when I replace mine in about a week.

I just had one question.
Could you possibly make a list of all the parts that will be needed for this repair such as gaskets, etc..
Based on your post I have this:
Fuel level sender unit
Fuel line clips (just in case)
Fuel Pump Gasket

Also if I just buy the fuel pump, will all the needed parts come with it? Thanks
 

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2005 gmc envoy_sle
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80 Posts
I'm going to be replacing my sender as well, so this write up is a huge help. Also, thanks for the line in the retaining clips. I'll head to pep boys today and pick them up. Here goes nothing....
 

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2006 chevy trailblazer_ls_ext
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37 Posts
Denali430 and others,


Just how many miles do you have on your vehicles? Last january I bought a lease back EXT with 16,814 miles on it. It now has 32,000+ miles. Is it that common for GM fuel pumps to go out?

I traded a 2000 D Dak 4x4 in with 119,000 miles with the original fuel pump and filter. 25% of my miles were towing a boat or Travel trailer so the enigine and fuel pump and filter got a good work out.


Chris
 

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2005 gmc envoy_denali_xl
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Mine has about 120,000 miles.
I just took out the fuel pump today and put the new one in and have encountered a few snags.
-First thing was the rear strap holding up the fuel tank. I was unsuccessful removing the entire strap. The bolt came out fine but the 'T' that holds the other side to the frame and needs to be rotated 90 degrees to get out wouldn't come out. I could not rotate the strap 90 degrees so I ended up just bending it down to get the tank down.
- The tube that comes from the fuel filler is extremely difficult to get off and just requires a lot of force after you loosen the worm gear clamps.
- Like others have said, the clips break very easily. Every clip I took off I broke. Now these clips are very difficult to find. The picture 3 posts up are NOT the ones you need. You need 800-041 and 800-023 which I could not locate at any auto parts store, only at rockauto.com.
- Before you take the fuel pump off use compressed air to blow away as much dirt as possible so it doesnt fall into the tank when you remove the pump.


Finally, I compared the old broken fuel sender unit to the new one and have found a few problems. The old one was pretty dirty and a little brake cleaner cleaned it right up. Also the float and lever were extremely loose and didn't the contacts didn't touch when the float moved up. Finally, one of the contacts was broken. I the old one with a multi-meter and before I did anything to the sender unit, I didn't get any reading on the multi meter. Once I cleaned it up I got a reading but ONLY when I held the float tight against the contacts since the lever was so loose. So there are multiple reasons the sender fails. Also the sender is completely open so if the float gets jolted around then it most likely loosens and the contacts break. I dont know why they didn't put a cover on it.

Here's what goes bad.
 

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2007 chevy trailblazer_lt
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how do you get those clamps off the filler hose? i was about to drop tank last night and i didnt know what the f they were so i just ragequit and bolted the tank back up until i could figure it out. couldnt you just use another style clamp?

also anyone have a good tip on removing the fuel lines or anything else to drop the tank? in my experience i break plastic fuel line connections so i really hate messing with that stuff. my main problem on this is its a lot harder to access everything.
how much slack do you have to get the tank down and undo everything?

i had to drop the tank in my 98 k2500 3 seperate times so i thought i could handle this no problem but its proving much more annoying. with my truck i had enough slack on the wires and fuel lines where i could get the tank on the ground to undo everything.
 

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2005 gmc envoy_denali_xl
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The clamps on the filler hose were just worm gear clamps but it was a huge pain to get off. As you probably saw there is a metal pipe the comes down from the filler, then a rubber hose connects the pipe to the tank. There is a decent amount of play in both the pipe and the hose so what I did was drop the tank with a jack until the hose/pipe prevented it from coming down any further and I put a jack stand under the tank. Then I took a stubby little screw driver and just slowly unscrewed the hose clamp. I suggest unscrewing the one on the tank side but this was the hard one for me as there is some plastic piece holding it to the hose so you can't rotate the hose clamp. So for mine the screw head was face up so I couldn't even see where I was unscrewing. Oh by the way it is a flat head. So it took me about 5 minutes to finally get it loosened! Then I had to ask my father to pull the tank towards the front of the car as I held the hose as it just didn't want to come off. Eventually it came free.

For the plastic clips, I just broke them all. Yes you can get them off without breaking them but you need 3 hands. You need 2 hands to unclip the little barbs on each end and then another hand to pull it out of the slot. I tried doing it myself and I could unclip one barb fine but once I went to the other one, the first barb would just pop right back in. So I got extremely frustrated and pried on it until it broke. Bad idea since the only place that carries the 5/8" clip is rock auto and I needed the car. 3/8" clip isn't too hard to find.

You also have a decent amount of slack. I was able to bring the tank down about 6-8 inches before the filler hose caught it. Then after I took that off, the electrical connections would catch the tank. There is some electrical connection by the filler hose that was a huge pain to take off also since the clip that you need to take off is at the top of the tank and your hand barely fits. Once the electrical is all disconnected then the fuel lines are easy as you can drop the tank a good foot without having to worry about the lines. There is one thing holding the lines to the top of the tank but it is very easy to unclip that and let the lines free.

Then the installation process was a little difficult as I had to lift the tank up myself and I was unable to jack the car up far enough to get the tank on a jack and push it under the car. I just slowly worked it up with bigger and bigger objects under each side of the tank until I could get a jack under it.

Good luck!
 

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2007 chevy trailblazer_lt
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i know which clamp you mean, this one was upside down too. i could not get to it in any easy way i might try to just jack up the whole rear instead of just one side of the car next go.

i have fuel line disconnect tools, but everything still likes to break on me.
 

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2005 gmc envoy_denali_xl
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Well at least you know they are good clips then. I was able to undo that clamp by just jacking up the driver side and like I said, I lowered the tank as much as possible. The easiest way to get to the screw is by going under the car and turning your body sideways so your feet are going out the driver side and your head is up in the underbody by the drive shaft. You can then reach above the tube coming in horizontally instead of vertically underneath.
 

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2007 chevy trailblazer_lt
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i got it down, must have spent half hour on that clamp haha...well i tried to take the spare out to make room, but add that to the list of **** that doesnt work on this 3 year old car...

im trying to get the pump out without removing any fuel lines haha...it seems it may be possible.
 

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2005 gmc envoy_denali_xl
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You can get to the pump but you most likely will not be able to get the ring off that holds the pump in place. I ended up having to hold a screw driver against the ring and hit it pretty hard with a hammer multiple times for it to even loosen up. Then a couple more hits and it spun free. I would suggest taking the tank all the way out since you dont want to risk puncturing the tank with the screw driver trying to do it under the car.
 

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2007 chevy trailblazer_lt
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well with any of these they dont just slide out, you need a hammer and chisel/screwdriver regardless. i did manage to replace the sender without removing any fuel lines or even pulling the tank out from under the car. but like i said i have done more fuel pumps on gm's over the years than i can even count. just not many without a lift, and i dont know why i keep doing it.

i will contribute my tips to the already helpful ones posted. consider the fact it is technically possible to do it without removing fuel lines, if you dont mind replacing clips DO take it out, it will be easier and probably take the same amount of time in the long run. putting the lock ring BACK while under the car sucked balls. really, you have no idea.

you can get the gasket off, just remove it via the bottom and install the new one the same way.

for the bucket, its a tight fit. i took it out twice in all, flip it upside down and pull it out bottom first. comes out way easier. theres a hole on the bottom you can grab.
attach the bucket BEFORE putting it back in, i have no idea why i thought i could put it in first, but dont. attach it outside the tank and put it all back in 1 piece.

taking off drivers rear wheel gives you a bit of extra room. every little bit helps. i think the spare would too, but like i said this one would come down.


well i probably wont be back, its my moms car and i never want to touch it ever again. have fun if you plan on doing this. i have a million tiny cuts on my hand and arms with gas in them hahaha
 

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2006 saab 9_7x
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Fuel clip part number

Here's the fuel line clip part number:

5/16" 21992748
3/8" 22717568
5/8" 21992746

At GmPartsGiant.com clip are 3.56$. You should order some before doing the job. In Montreal, GM sold each clip 9.70$ CAN.

On my SAAB 9-7x 2006 5.3L, to remove the tank you need to un-clip

1 x 5/16"
3 x 3/8"
2 x 5/8"

+ 1 optional 3/8 " clip on fuel pump/line
+ 1 optional 5/8 " clip on fuel pump/line



Sebastien
 

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2004 gmc envoy_slt_xuv
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My LWB Fuel Module Replacement (no pics, sorry)

I just changed my Fuel Pump module (FPM) over the weekend. Was a lot like others I have done.

My Friday afternoon:
Because my truck came from Florida, it was super clean underneath and everything came apart easy. One problem though, hoping no one else has this happen....

During removal, when I was tugging on the Filler Tube rubber hose attached to the back of the tank, I tugged too hard and broke it loose from the Tank, OUCH :bonk:

I had noticed other times I was under the truck, that it looked like it was seeping gas around this fitting where it attached to the Tank, so I figured it had been cracked for a while and my tugging broke it the rest of the way.

Friday evening:
I continued with the project and got the tank out from under the truck. Shook my head a few times and started brainstorming a fix, if not a new tank would be required. I considered Epoxy I had lying around, also found some J-B Weld (another type of Epoxy) and Super Glue. I decided to visit the Auto Parts Store and see what magic they had on the shelf. Found a Plastic Repair Super Glue and a Plastic Repair Epoxy. I chose to buy both and headed home.

I removed the old FPM, looked original but was not rusty at all, cleaned the area and installed the new FPM (both old and new FPM were a Bosch Product with the same GM Part number on them). Lock ring was tough to get started, but eventually it twisted into place. reconnected the 2 fuel lines and went back to the broken neck repair. I cleaned the area with Brake Clean and waited for it to dry, matched up the parts to confirm fit and chose the Plastic Super Glue. It was runny and seemed to cure slowly (kinda cold in the Garage, 'cause I didn't want to use the Garage heater with all the fumes in there) So I left it for a while to cure, later I applied more glue around the joint and left it for the night.

Saturday morning:
I tugged a bit on the fitting and it seemed secure, so I applied more super glue to the joint to insure it had the best chance to survive. I used a hair dryer to speed it up a little.

A couple hours later, the tank went back in and I hooked up the hose last, using a film of grease in both ends of the hose. It went right on and I tightened both clamps.

Completed the job, primed the pump and it started right up, got it back on the ground and the test drive went perfect. I will monitor the repair and see if it holds up, otherwise a new tank seems the easiest solution. Found it on GM Parts Direct for 305.00? (25 Gal) plus shipping.

Has anyone else heard of a TSB or something that deals with this Filler Neck problem?

As a side note, I was able to remove and reuse all of the plastic clips that retain the lines :thumbsup:, I have heard a few say theirs were brittle and broke easily.
 

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2006 chevy trailblazer_ls
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Just finished replacing the sender unit. Would like to share a few thoughts, there is NO need to remove the clips just push in on the U and disconnect as SAAB person said. There was still pressure in the fuel system after pulling fuel pump relay and letting vehicle stall, so you need to find the shrader valve and relieve the fuel pressure (top front of engine drivers side black cap) You must buy all three size fuel line clips just in case, also purchase the rubber hose that connects tank to the fuel fill line so that you can just cut the old one off. Clean around the fuel pump very well before and during removal, compressed air and vacuum, I blew it off twice but still had rust fall in tank. I pulled the fuel pump straight out intact replaced sender and sent the assembly straight back in, it's tight but keep it square and you'll be good. As stated earlier be sure both tank straps are hanging from their keyed slots before raising the tank back into position. Job took me five hours.:bonk:
 
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