Been runnin on empty for 40 miles!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,952
Reaction score
12,188
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Like the Eagles song except no tape deck in the truck.
The old 77 has an aftermarket aux tank. PO said it is only 10 gallons. Asked him why he thought that. Said cause when it’s on E it only takes 10 gallons…reasonable logic.
But the tank looks roughly the same size as the OE tank. =20 gal. Little shorter but more square. (Why aftermarket tank setups didn’t just include oe GM tanks??? This one looks like it weighs 90lbs, lol).
Anywho, both tanks were plumb full when I bought it. And since it is not a big block 4/4 ton rolling on flintstone wheels and has a 3.07 rear end, it’s way better on fuel!
Ran the pass side tank down to 1/2. Figured out there’s a short in the toggle switch that pegs the gauge on that side…sometimes.
Switched to aux tank. Gauge has been coming down like normal. Haven’t paid attention to miles other than it just turned 70.0k. And I missed 69999.9 but ….
Been empty, gauge not even bouncing. Hit 70040 tonight and still pulling hard on the aux tank.
Wonder what (new) sender is in that side? Tank kinda looks the same depth as oe and both senders new. Wonder if it’ll run another 6-9 gallons before running dry?
In other news, painted up a bunch of the interior trim pieces and got the headliner out in one piece. At least there’s a half a coat of brown paint on the cab ceiling. Remarkably consistent scratch coat. Looks decent and is clean.
No pics of the boring stuff like crusty gas tanks…
You must be registered for see images attach
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,952
Reaction score
12,188
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Looks like it was just under 1/8 at 69996.9 Hahaha
If that was accurate it would have 2-3 gallons left. The 86 runs out of gas aboot 10-15 miles after the gauge quits bouncing.
This thing don’t get 20 mpg!
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
the only thing I would say is what is the fuel tank switching valve, is it the motorized pollack valve? or is it the old solenoid? Theres a chance that its pulling gas out of the other tank and that tank if its the old style. also would be interested in seeing what the aux tank looks like
 

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,249
Reaction score
15,819
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
@Grit dog ,how is the aux tank held on? On my 75K20 there are 2 bolts through the tank and the bed was drilled for them to go through. Top art "stove" bolt style heads with fitted oblong washers, while the "nuts" on the bottom of the tank are flush 3/8 drive square holes to tighten things up. I don't remember what the brand was, but it had a single toggle that changed the flow. Worked great while I had it on, held about 20-22 gallons. I always ran on the aux til the gage was down to a quarter then switched to the main(pass).........Also, that is my FAVORITE Jackson Browne song........It will be played at my funeral/celebration of life service!!!.....lol
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,952
Reaction score
12,188
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Hahaha oops
Eagles, Jackson Brown, who’s counting….my bad.

This one is bolted to the frame, some u bolt looking brackets. Honestly was installed by a hack. Filler neck sticks out of a poorly cut hole in the bed at a weird angle. And bed side dented up looks like upon install.
Back to why not just get some oe parts, cut a nice hole, voila?
 

SquareRoot

Full Access Member
Joined
Mar 18, 2017
Posts
4,187
Reaction score
8,007
Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
Like the Eagles song except no tape deck in the truck.
The old 77 has an aftermarket aux tank. PO said it is only 10 gallons. Asked him why he thought that. Said cause when it’s on E it only takes 10 gallons…reasonable logic.
But the tank looks roughly the same size as the OE tank. =20 gal. Little shorter but more square. (Why aftermarket tank setups didn’t just include oe GM tanks??? This one looks like it weighs 90lbs, lol).
Anywho, both tanks were plumb full when I bought it. And since it is not a big block 4/4 ton rolling on flintstone wheels and has a 3.07 rear end, it’s way better on fuel!
Ran the pass side tank down to 1/2. Figured out there’s a short in the toggle switch that pegs the gauge on that side…sometimes.
Switched to aux tank. Gauge has been coming down like normal. Haven’t paid attention to miles other than it just turned 70.0k. And I missed 69999.9 but ….
Been empty, gauge not even bouncing. Hit 70040 tonight and still pulling hard on the aux tank.
Wonder what (new) sender is in that side? Tank kinda looks the same depth as oe and both senders new. Wonder if it’ll run another 6-9 gallons before running dry?
In other news, painted up a bunch of the interior trim pieces and got the headliner out in one piece. At least there’s a half a coat of brown paint on the cab ceiling. Remarkably consistent scratch coat. Looks decent and is clean.
No pics of the boring stuff like crusty gas tanks…
You must be registered for see images attach

the only thing I would say is what is the fuel tank switching valve, is it the motorized pollack valve? or is it the old solenoid? Theres a chance that its pulling gas out of the other tank and that tank if its the old style. also would be interested in seeing what the aux tank looks like
Lol, I was scratching my head thinking, someone must be having a mushroom party.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,952
Reaction score
12,188
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
the only thing I would say is what is the fuel tank switching valve, is it the motorized pollack valve? or is it the old solenoid? Theres a chance that its pulling gas out of the other tank and that tank if its the old style. also would be interested in seeing what the aux tank looks like
It’s a single wire, 3 port aftermarket solenoid. No return lines. And based off of switching back n forth several times it’s only pulling from the tank selected.
What it looks like? Ugly square old welded steel tank covered in 1970s era rustproofing that appears to have the same sender as an OE tank (from what I can see between the cab n bed.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
It’s a single wire, 3 port aftermarket solenoid. No return lines. And based off of switching back n forth several times it’s only pulling from the tank selected.
What it looks like? Ugly square old welded steel tank covered in 1970s era rustproofing that appears to have the same sender as an OE tank (from what I can see between the cab n bed.
if its steel i wonder if it maybe is rusty inside compared to the normal gas tank and the wiper on the level sender isnt getting full travel
And interesting
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Hahaha oops
Eagles, Jackson Brown, who’s counting….my bad.

This one is bolted to the frame, some u bolt looking brackets. Honestly was installed by a hack. Filler neck sticks out of a poorly cut hole in the bed at a weird angle. And bed side dented up looks like upon install.
Back to why not just get some oe parts, cut a nice hole, voila?
if you can find a good bedside and filler neck id think that would be the best fit, but i would do return style fuel system at the same time if i were you but its all your choice of course.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
at least its not an aux tank on a 1967-1972 chevy, this is an aftermarket solution someone could have ended up stabbing a hole in your bed floor for :superhack:
You must be registered for see images attach
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,952
Reaction score
12,188
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
if its steel i wonder if it maybe is rusty inside compared to the normal gas tank and the wiper on the level sender isnt getting full travel
And interesting
Possible. Sender is new though and it went perfectly to empty and stopped there on the gauge.
Not really an issue. Just perplexing. If it runs for 75 miles on empty that tank just has a nice reserve.
It does look like it was installed by a chimpanzee though…


You must be registered for see images attach
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Possible. Sender is new though and it went perfectly to empty and stopped there on the gauge.
Not really an issue. Just perplexing. If it runs for 75 miles on empty that tank just has a nice reserve.
It does look like it was installed by a chimpanzee though…


You must be registered for see images attach
midget g-hole
 
Top