Dual Tanks Fuel switch delete

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.

1

1974Blueflame

Junior Member
Joined
Oct 10, 2024
Posts
3
Reaction score
2
Location
east bay
First Name
cole
Truck Year
1974
Truck Model
K1500
Engine Size
350 V8
I have a fuel switch issue and don’t really want to have to switch between tanks has anyone just configured the hoses into a T going to the fuel pump?
 
WFO

WFO

Full Access Member
Joined
Jan 6, 2017
Posts
3,694
Reaction score
5,046
Location
Texas Panhandle
First Name
Dan
Truck Year
1986
Truck Model
K20
Engine Size
350
1974Blueflame said:
I have a fuel switch issue and don’t really want to have to switch between tanks has anyone just configured the hoses into a T going to the fuel pump?
Click to expand...
I did on a 1980 company truck, while doing a job out of town. Worked fine for the couple of months it took to finish the job, then fixed it when we got back home.
The tanks will equal out, and the gauge was the most accurate after it had been parked for a while.
 
Grit dog

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,981
Reaction score
12,246
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
1974Blueflame said:
I have a fuel switch issue and don’t really want to have to switch between tanks has anyone just configured the hoses into a T going to the fuel pump?
Click to expand...
No return line(s) that will work. 3 port sender and return line fuel pump, that will not work.
 
WFO

WFO

Full Access Member
Joined
Jan 6, 2017
Posts
3,694
Reaction score
5,046
Location
Texas Panhandle
First Name
Dan
Truck Year
1986
Truck Model
K20
Engine Size
350
Grit dog said:
No return line(s) that will work. 3 port sender and return line fuel pump, that will not work.
Click to expand...
Worked for me. I don't make this stuff up.
Didn't even mess with the return line. I reckon it only returned to the one tank that had been previously switched to, but the tanks equalized themselves anyway.
 
bucket

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,447
Reaction score
28,363
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
WFO said:
Worked for me. I don't make this stuff up.
Didn't even mess with the return line. I reckon it only returned to the one tank that had been previously switched to, but the tanks equalized themselves anyway.
Click to expand...

So you are saying that with the supply lines tee'd together, the tanks balanced due to a siphon effect through the supply line? Makes sense.

I'm sure there's going to be a scenario where that setup could possibly cause an issue though, if someone did it that way permanently.
 
  • Like
Reactions: WFO
R

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,472
Reaction score
8,767
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
bucket said:
So you are saying that with the supply lines tee'd together, the tanks balanced due to a siphon effect through the supply line? Makes sense.

I'm sure there's going to be a scenario where that setup could possibly cause an issue though, if someone did it that way permanently.
Click to expand...
It's going to cause an issue eventually if/ when 1 tank runs low enough to lose prime and siphon effect. NBD I just don't want to be the guy adding fuel to the low tank at the side of the road.
 
C

CalSgt

Full Access Member
Joined
Oct 3, 2021
Posts
1,704
Reaction score
3,773
Location
CA
First Name
Casey
Truck Year
1980
Truck Model
Chevy K-10 Custom Deluxe
Engine Size
350
Ricko1966 said:
It's going to cause an issue eventually if/ when 1 tank runs low enough to lose prime and siphon effect. NBD I just don't want to be the guy adding fuel to the low tank at the side of the road.
Click to expand...
^^^ This

If the system would work well without a selector valve GM wouldn’t have spent the money putting them in.

If you need to hack it to get by for a while, then so be it.

Whichever tank has less resistance to pull the fuel from may end up getting ran dry faster than the other. When my selector valve went bad it pulled from both tanks, too many times one tank would run dry and would not even be able to start unless I primed the carburetor even after adding gas to the empty tank.

You’re better off replacing or repairing the selector valve (common failure), switch, or wiring.
 
Grit dog

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,981
Reaction score
12,246
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
CalSgt said:
^^^ This

If the system would work well without a selector valve GM wouldn’t have spent the money putting them in.

If you need to hack it to get by for a while, then so be it.

Whichever tank has less resistance to pull the fuel from may end up getting ran dry faster than the other. When my selector valve went bad it pulled from both tanks, too many times one tank would run dry and would not even be able to start unless I primed the carburetor even after adding gas to the empty tank.

You’re better off replacing or repairing the selector valve (common failure), switch, or wiring.
Click to expand...
Good point. I assumed they’d pull somewhat the same until maybe low fuel level.
Which brings out the other workaround of connecting both tanks on the bottom to equalize. That definitively works. Just difficult to execute as a safe and long term solution.
 
fast 99

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
2,033
Reaction score
2,947
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
Grit dog said:
Which brings out the other workaround of connecting both tanks on the bottom to equalize.
Click to expand...
Done on larger [higher] over the road trucks.

Our company used low profile trucks. Factory would not install dual tanks like that because the possibility of damage and fuel spill.
 
WFO

WFO

Full Access Member
Joined
Jan 6, 2017
Posts
3,694
Reaction score
5,046
Location
Texas Panhandle
First Name
Dan
Truck Year
1986
Truck Model
K20
Engine Size
350
bucket said:
So you are saying that with the supply lines tee'd together, the tanks balanced due to a siphon effect through the supply line? Makes sense.

I'm sure there's going to be a scenario where that setup could possibly cause an issue though, if someone did it that way permanently.
Click to expand...
Exactly

Like I said it was a temporary fix while we were working out of town staying at a Motel, and couldn't be without a truck.
I made sure that the fuel levels never got low.
 
Tyger13us

Tyger13us

Full Access Member
Joined
Jan 13, 2012
Posts
275
Reaction score
24
Location
BFE,Ut
First Name
Jeff
Truck Year
78
Truck Model
k10
Engine Size
450hp/357cid
9 times out of 10, its been the switch on ALL my twin tank trucks, i take a working switch out of one of my trucks and plug it in the none working one and it works again.
Ive never had a bad selector valve, some times the plug gets full of crap? or the gauge in the tank goes bad..
Just my personal exp.
 
85 red GMC

85 red GMC

Junior Member
Joined
Sep 7, 2021
Posts
13
Reaction score
13
Location
SW Florida
First Name
Bradley
Truck Year
1985
Truck Model
K1500
Engine Size
305
Ricko1966 said:
It's going to cause an issue eventually if/ when 1 tank runs low enough to lose prime and siphon effect. NBD I just don't want to be the guy adding fuel to the low tank at the side of the road.
Click to expand...
Since you have a switch and they (at least mine) do not tend to stall in the switching process with engine running, what is the benefit of eliminating the switch. Looks like of lazy to me.
 
R

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,472
Reaction score
8,767
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
85 red GMC said:
Since you have a switch and they (at least mine) do not tend to stall in the switching process with engine running, what is the benefit of eliminating the switch. Looks like of lazy to me.
Click to expand...
I don't want to eliminate anything. I was telling the O.P. the downside of not fixing it right.
 
You must log in or register to reply here.

Similar threads

F
Dual fuel tanks and valves
2
Replies
17
Views
1K
Doppleganger
Doppleganger
N
Fuel Sending Unit Odd ohm Reading
Replies
0
Views
206
noelsautomotive
N
S
Dual fuel tank not switching when i hit switch
Replies
1
Views
436
Robert Bare
R
D
Fuel Gauge Tank Selector switch and valve
Replies
9
Views
350
Sgt Gus
Sgt Gus
RKBMKZ
Pollack Tank Selector Valve
Replies
11
Views
1K
CalSgt
C

Latest posts

Forum statistics

Threads
44,193
Posts
951,237
Members
36,315
Latest member
aubiexx
Top