# Sending unit Fuel pump



## RichG53 (Sep 16, 2008)

Are the fuel gauge sending unit and fuel pump separate or a combined units ???
Thanks !!!


----------



## partsguy08 (Sep 1, 2008)

Assuming it is the truck in your sig. Yes it is a complete module. Sending unit and pump all in one. Replace your fuel filter too.


----------



## 70monte (Feb 5, 2008)

How about a 98 K1500? My fuel gauge quit working after the truck sat for quite awhile without it being driven. The gauge mostly reads from 3/4 tank to a full tank and occasionally it drops all the way to empty before going back up.

Wayne


----------



## APLC (Nov 25, 2008)

yep sounds like a sending unit when u get issues with your fuel gauge. Yeah i believe on most mid 90's Chevy trucks the sending unit and fuel pump are all in one, dont go with a cheap replacement had to learn that a few times good luck should be an easy fix though


----------



## 2COR517 (Oct 23, 2008)

You CAN buy just the sending unit. Basically it's the whole works less the pump.

http://www.autozone.com/autozone/ca...uel+Tank+Sending+Unit&searchText=sending+unit

If your pump is fairly new, this would be fine. Considering how little fun changing the pump is, I would do everything at once. The recommendation seems to be AC Delco pumps. B&B, do you concur on ACD?


----------



## 70monte (Feb 5, 2008)

My pump is not very new as it has about 77,000 miles on it. Its an AC-Delco replacement that I replaced quite a few years ago. Its probably not worth just replacing the sending unit with the mileage I have on mine.

Wayne


----------



## B&B (Nov 4, 2006)

Total waste of time and effort to change only the sender or only the pump while they're both removed from the tank on anything pre-'03 GM with the problematic history record they both have on todays gasoline. 

Change them both to a current design as they'll be content on todays alcohol impregnated gasoline causing those issues to become null and void.


----------



## RobMI (Sep 18, 2009)

Make sure to check the 4pin square connector at the sending unit. These are very prone to fail, napa includes a new connector with pigtail with some of the pump/sending unit combos now. If not included it is available separately. I replace these connectors due to pin burn out at the shop all the time.


----------



## B&B (Nov 4, 2006)

RobMI;830756 said:


> Make sure to check the 4pin square connector at the sending unit. These are very prone to fail, napa includes a new connector with pigtail with some of the pump/sending unit combos now. If not included it is available separately. I replace these connectors due to pin burn out at the shop all the time.


Standard procedure during a pump or sender change on a GM.


----------



## 70monte (Feb 5, 2008)

B&B;830747 said:


> Total waste of time and effort to change only the sender or only the pump while they're both removed from the tank on anything pre-'03 GM with the problematic history record they both have on todays gasoline.
> 
> Change them both to a current design as they'll be content on todays alcohol impregnated gasoline causing those issues to become null and void.


What do you mean change them to the current design. Are the new Delco replacements for my year truck a current design or do I have to specify a different year pump that will work.? thanks.

Wayne


----------



## B&B (Nov 4, 2006)

No just a currently manufactured pump for whatever the application is. After E10 became prevalent manufactures began updating replacement fuel system components across the board (mostly for older vehicles) so the replacement parts would be fully ethanol compatible.


----------



## mkwl (Jan 21, 2005)

What's the process/costs for changing out the fuel pump? Hopefully I don't need to do one anytime soon, but I'd just like to know.


----------



## B&B (Nov 4, 2006)

Lift the bed off, disconnect the lines, unplug the wire connector and pull the pump assembly up out of the tank. I have them to under an hour start to finish.


----------



## partsguy08 (Sep 1, 2008)

A good aftermarket pump will cost around $300.00 (give or take a hundred), while a GM pump run around $500-$600. Stay away from off brand pumps, go to the dealer and buy a Delco pump or buy a Delphi from a local parts store. This is a part that WILL leave you stuck.


----------



## partsguy08 (Sep 1, 2008)

B&B;832441 said:


> Lift the bed off, disconnect the lines, unplug the wire connector and pull the pump assembly up out of the tank. I have them to under an hour start to finish.


sopping up all the gravypayup lol


----------



## mkwl (Jan 21, 2005)

B&B;832441 said:


> Lift the bed off, disconnect the lines, unplug the wire connector and pull the pump assembly up out of the tank. I have them to under an hour start to finish.


Yikes- pulling off the bed? It's not easier to drop the tank? How does one go about pulling the bed?


----------



## 2COR517 (Oct 23, 2008)

mkwl;832742 said:


> Yikes- pulling off the bed? It's not easier to drop the tank? How does one go about pulling the bed?


It's easier than it sounds. 8 bolts hold the bed down. Three screws on the filler neck. You can actually jack up just the drivers side up a foot or two if you want. Don't take the pass side bolts all the way out.

You will get the time back easy. Especially if the tank is full. And the tank is always full when the pump dies. Plus you don't have to deal with rusty bolts on the tank straps.


----------



## woodchuckcanuck (Sep 15, 2009)

I'm currently suffering this same problem. Take the box off? Sounds reasonable. But if the tank straps are that bad, might as well replace that too while being that committed to the repair.


----------



## jblatti13 (Jan 24, 2009)

i just had to do all of this last week on my 90 1500.... taking the bed off is definitely the way to go... i had to replace rear fuel lines, sending unit and pump, and ended up getting a new tank as well... the beds held down by 8 bolts, the rear 2 youll have to remove the bolts for the hitch mount to get to the bed bolts... get the bed off and everything is right there and wide open for you to get to. sending unit was about 150 fuel lines 160 tank 125 and pump was about 85... definitely buy ac or delphi pump, not worth it using aftermarket there... the sending unit i believe was dorman.. they make most of the lines and stuff for these trucks, cheapest i found was at oreailly's ( murrays auto parts) if you have one near by. good luck with it, not too bad of a job.


----------



## 2COR517 (Oct 23, 2008)

Those way back bed bolts should come off with a ratchet, rather than pulling the hitch bolts.


----------



## mkwl (Jan 21, 2005)

Do any of the wires/brake/fuel lines have to be removed?

Where are all 8 bolts located, and how much does 1 side of the bed weigh?


----------



## B&B (Nov 4, 2006)

mkwl;837598 said:


> Do any of the wires/brake/fuel lines have to be removed?


 Only the rear lighting harness. You'll find the connector plug near the back on the driver side. It will be connected to a junction box, just disconnect it there. Some trucks also have a braided ground between the bed and frame, usually near the front on the driver side, so don't overlook it.



mkwl;837598 said:


> Where are all 8 bolts located, and how much does 1 side of the bed weigh?


Slide under there and look Matt you'll see them. Four near the back on the inboard side of the frame rails and four near the front on the outboard side.

Less tailgate a shortbed bed weighs right around 300 lbs.


----------



## jblatti13 (Jan 24, 2009)

yes there is a rear lighting harness, and a ground wire attatched directly to the frame from that, so you need to remove that separately. braided ground wire on my truck was from tank filler neck to frame right above tank. i have a 6/5 ft bed and me and my father lifted it off and moved the bed about 15 feet by ourselves. not reccommended by most but im only 155lbs and i didnt get hurt so.most people advised me just to move the bed back a few feet and let it rest on the bumper. i took i completely off to get a good visual of everything. i wish i had taken pics.my short bed only had 6 bolts total. all are attatched to the bed rails, so get under there and follow those until you see a hole just big enough for a deep well socket to get into. there's your bolts. definitely need a breaker bar. mine were tough, couldnt do it with a 250 ft lb tq air gun. get a good bar and you'll get em off. once you get those bolts and the wires apart, move the bed and you'll see it all. you can disconnect the lines from the sending unit right there. the sending unit comes out pretty easy with a flat head or a tap, pushing it counter clockwise from the tank. you;ll get a good idea when the beds off what you'll need to do. way easier than dropping the tank in my book.


----------



## Plowinpro03 (Dec 18, 2007)

I always thought it was easier to drop the tank then lift off the box? Then again I have a tahoe..haha. Why not just cut an access door in your bed?


----------



## 2COR517 (Oct 23, 2008)

With a Tahoe/Sub, I guess I would rather drop the tank. But I have heard of guys cutting access doors with those.......


----------



## RichG53 (Sep 16, 2008)

Why would any one want to CUT a hole in there trk bed or floor of any type vehicle ????? Just more problems down the road ....


----------



## mkwl (Jan 21, 2005)

RichG53;838294 said:


> Why would any one want to CUT a hole in there trk bed or floor of any type vehicle ????? Just more problems down the road ....


I actually half thought about this for a second, but then remembered I'd probably destroy a lot in the process lol, so a no go...


----------



## 2COR517 (Oct 23, 2008)

Pulling the bed is a piece of cake Matt.


----------



## mkwl (Jan 21, 2005)

2COR517;838451 said:


> Pulling the bed is a piece of cake Matt.


Alright- thanks for the words of encouragement! Hopefully my fuel pump will last for a while (so far so good- knock on wood), but just in case, I like to know what to do if something does fail- be proactive lol!


----------



## partsguy08 (Sep 1, 2008)

Had a GM tech that I used to work with, He went to Canada every year. A week before he would leave, he would loosen and retighten all of his bed bolts for just this reason. Replaced the fuel pump on the side of the highway once. He was back on the highway in less than an hour.


----------



## 2COR517 (Oct 23, 2008)

I was going to suggest that Matt. Get all the bolts loosened up, take the drivers side out. Prop the side of the bed up, then you'll know exactly what you need to do when the time comes. Give the sending unit a good coating of Fluid Film, that mill make removal easier. And when you put your bed bolts back in, put something like teflon pipe sealant on them. That will keep them from rusting, and they will come out nice and easy next time.


----------



## just me (Oct 15, 2009)

So on my 2000 K1500 with the erratic fuel level readings and the "low fuel " light coming on, that is the sending unit itself and not a weak/bad ground ? 
FWIW, I use "anti-sieze" compound on anything I take apart and put back together here. It even stays on exhaust manifold bolts.


----------



## BigLou80 (Feb 25, 2008)

2COR517;832756 said:


> And the tank is always full when the pump dies.


why is that? mine died today on a narrow street with 30 cars behind me could have been worse I guess

what size are the bolts that hold the bed on ?


----------



## 2COR517 (Oct 23, 2008)

BigLou80;874743 said:


> why is that? mine died today on a narrow street with 30 cars behind me could have been worse I guess
> 
> what size are the bolts that hold the bed on ?


should be 18mm


----------



## RichG53 (Sep 16, 2008)

I don't suppose there is any advance notice the pump is starting to go ????
It just goes ????


----------



## 2COR517 (Oct 23, 2008)

My experience is they give you anywhere from 10 miles to 10 seconds warning......


----------



## RichG53 (Sep 16, 2008)

WOW !!! I hope I don't blink when it happens....I'll miss it....


----------

