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Does' fuel tank selector valve just quit working?

kat

Sr. Member
Joined
Jul 22, 2015
Messages
892
Loc.
Bristol
Do they just quit working or start leaking? The reason I'm asking is all of a sudden and not all the time but my 76 will start raising cane like its running out of gas while Im going down the road. I can switch it to Aux and it will smooth out and run fine. I have recently replaced the electric fuel pump (old one quit working) and changed the fuel filter I have between the valve and pump. Don't see any leaks as of yet.
The valve still feels very stiff and I can hear and feel it 'clicking' when I switch tanks. Just wondering what I need to look for. Thankis
 

Johnnyb

Contributor
Sr. Member
Joined
Nov 19, 2001
Messages
436
Loc.
Flagstaff
As I recall, you can take those valves out and take them apart. There's a little cone inside that does the job of selecting which tank you're using and probably a couple of o-rings.

The switch on the dash actually is a double pole double throw. That means the switch is capable of running an electric selector valve. I don't have a part number but they're pretty common.

I guess what I'm saying is it's pretty easy to get rid of the mechanical switch that nobody knows how to use anyway and replace it with an electric tank selector controlled by the switch on your dash.

The only downside is the mechanical switch, in the vertical position, is pretty effective theft prevention!

JB
 

Broncobowsher

Contributor
Total hack
Joined
Jun 4, 2002
Messages
33,359
Just O-rings in there. Yes, they can age and do bad things. Air leak (leaking into the valve) can cause havoc.
Or the pickup sock in the tank can cause issues. Stopping the flow, keep driving, shake the junk off and it will start sucking again.
 
OP
OP
kat

kat

Sr. Member
Joined
Jul 22, 2015
Messages
892
Loc.
Bristol
Don't want to go with electric switch but thanks for the info. I just filled both tanks up and hate to loose any gas on the ground...precious materials.

Broncobowsher is there a way to test the valve for air leaks while still on?? Soapy water??
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,747
Loc.
Ridgefield WA
If you use an air hose in the fuel filler neck, sealed with a shop rag, you can find most leaks between the tank and pump.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,830
you don't even have to take the valve out to change the 0-ring the cap unscrews. you do have to take the handle off. nothing special standard threads righty, titie, lefty, loosey.
 

YNOTBOB2007

Full Member
Joined
Oct 2, 2007
Messages
180
Did you find the problem? Since the problem disappears when switching to your auxilary tank, could something be acting up in your main tank? Rust or bad gas?
 
OP
OP
kat

kat

Sr. Member
Joined
Jul 22, 2015
Messages
892
Loc.
Bristol
Did you find the problem? Since the problem disappears when switching to your auxilary tank, could something be acting up in your main tank? Rust or bad gas?
No I have not found the problem. And yes I have been a professional parts changer since. Replaced gas line from valve to main tank. Im thinking its my sock on the sending unit in tank pulling sucking together. Gonna do some more research. Even though the sending unit is a few years old, that is the only thing left.
 
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