How rough is replacing the fuel pump in a 1990 k5? Mine just went out and I'm contemplating doing it myself. Also, assuming I do it, what other things should I check out or replace while I have the fuel tank dropped?
CK5
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Replacing fuel pump
- Thread starter sdjohn99
- Start date
Assuming it doesn't have 31 gallons of fuel it's not a bad job. You just need to drop the tank down some to get your hands on top to disconnect the fuel supply and return lines (they are threaded fittings) and also the vent hose. Don't forget to remove the filler neck hose as well (I find it easier to remove it at the tank and slide it far enough onto the fill neck to clear the tank fitting).
This is also a good time to use a DVOM (Digital Volt Ohm Meter) and check the sender for proper resistance to make sure your gauge reads properly (GM senders are 0-90 ohms).
This is also a good time to use a DVOM (Digital Volt Ohm Meter) and check the sender for proper resistance to make sure your gauge reads properly (GM senders are 0-90 ohms).
Here's what I do...
1. remove metal filler panel between bumper and body
2. remove 3 bolts holding the rear of the gas tank skid and bend it down to the ground
3. put a floor jack under the tank
4. remove the nuts for the gas tank straps
5. disconnect fuel filler tube hose and vent hose
6. disconnect electrical plug drivers side frame above axle and ground strap driv side frame top behind the wheel
7. lower tank enough to remove the feed/return/vapor lines from the sender
8. lower tank the rest of the way or even pull it out behind the truck so you can work on it easier. This can be tough if it has lots of gas in it.
9. very important, take compressed air and blow dust off the top of the tank and around the sending unit. This is to keep crap from dropping into the tank.
10. remove sending unit and replace pump or both
I've got this down to about an hour and a half, from start to back together, and that includes the trip to the parts store with the old pump in hand so they can warranty it for me. Next time it fails I'm buying a better quality pump. And BTW, don't buy a cheap pump, spend the extra money for a decent one like a Bosch or an AC Delco.
1. remove metal filler panel between bumper and body
2. remove 3 bolts holding the rear of the gas tank skid and bend it down to the ground
3. put a floor jack under the tank
4. remove the nuts for the gas tank straps
5. disconnect fuel filler tube hose and vent hose
6. disconnect electrical plug drivers side frame above axle and ground strap driv side frame top behind the wheel
7. lower tank enough to remove the feed/return/vapor lines from the sender
8. lower tank the rest of the way or even pull it out behind the truck so you can work on it easier. This can be tough if it has lots of gas in it.
9. very important, take compressed air and blow dust off the top of the tank and around the sending unit. This is to keep crap from dropping into the tank.
10. remove sending unit and replace pump or both
I've got this down to about an hour and a half, from start to back together, and that includes the trip to the parts store with the old pump in hand so they can warranty it for me. Next time it fails I'm buying a better quality pump. And BTW, don't buy a cheap pump, spend the extra money for a decent one like a Bosch or an AC Delco.
WJACKSON11X
1/2 ton status
Or do it the lazy way and cut an access panel in the rear floor.
If you have a nice ride, I don't recommend it. I had to do mine that way out on the trail, so I didn't have much choice.
If you have a nice ride, I don't recommend it. I had to do mine that way out on the trail, so I didn't have much choice.lugnut
1/2 ton status
ahhh
I was just going to say some shackle flips are in order with the dropping of the tank.
FunHome
Registered Member
Thanks guys!! This thread really helped! I just got the tank pulled out of my 1991 K5 and found the rubber connecting The pump to the sending unit was split!! Probably going to go ahead and put a new pump in while I have it out!
FYI, the truck had the surge at idle and bogged out while under power...
Question, I found just a little wet spot under one of the tank straps and it's kinda rusted... Not real bad... Should I replace the tank?
FYI, the truck had the surge at idle and bogged out while under power...
Question, I found just a little wet spot under one of the tank straps and it's kinda rusted... Not real bad... Should I replace the tank?
Tough to tell...if it's surface rust, is it likely that is just water sitting there that hasn't evaporated? Or is it rust that is worse, and may be the actual tank leaking?
I personally would recommend replacing the tank if you have any inkling that it is leaking, or may in the near future. I don't believe the tanks are that pricey. You'll need one specifically for TBI, '87-91.
When I replaced my tank, I also painted the areas on the tank where the straps/cushions contact it, to try and delay rust as long as possible. I also drilled drainage holes in the skid plate since mine rides almost on the tank itself.
I personally would recommend replacing the tank if you have any inkling that it is leaking, or may in the near future. I don't believe the tanks are that pricey. You'll need one specifically for TBI, '87-91.
When I replaced my tank, I also painted the areas on the tank where the straps/cushions contact it, to try and delay rust as long as possible. I also drilled drainage holes in the skid plate since mine rides almost on the tank itself.
