Fuel Valve replacement (I made it worse)

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Shawn Wheeler

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1984
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K10
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305
Fuel Valve replacement (I made it worse)

1984 Chevy K10. 98% stock. Dual fuel tanks. Stock Rocker switch on the dash. Fuel valve is a six port valve, (just replaced)

Back story – Filled up the left tank. Moved the rocker switch to the left tank. Fuel gauge read full.

Drove a mile down the road. The truck started to die, moved the rocker switch back to the right tank and the truck continued to run. My brain says the valve between the tanks is bad. I didn’t do any diagnostics. I just bought a new valve.

Today

I replaced the valve. (What a pain in the neck!)
Got it all put back together, started the truck and now leaks. YAHOO.

Note the trucks fuel gauge is reading ½ on the left tank. I flipped the rocker switch. No change on the fuel gauge. Back and forth a few times, no change.

Crap, now I am worse off.

I would love some recommendations on what to check please.
 

Girth

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Gonna be watching this myself. New to me '84 C10 also supposedly has tank/valve issues. Previous owner gave me a new valve with the truck, told me it wouldn't switch to the right tank. No biggie... I really only need one. The fuel gauge reads Full when the tank is near empty though, and the needle is buried well past full when the tank is full.

I think the signal for the gauge goes through that switch? I bought a new switch to stab in, since my switch doesn't feel right, but have yet to do any real troubleshooting either. Maybe that switch is your culprit?
 

Shawn Wheeler

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I just watched a video on YouTube. The person replaced both. The dash switch according to the video is under 20 bucks. I think I will try that two. Just bugs me that it got worse than when I started. Keep me posted, I will do the same.
 

chevytech87

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Watching as well, replaced mine once already. Fixed it for about a year and a half, then last Thursday it quit again. I replaced both the switch and valve last time, hoping it’s the valve this time. Switch seems* to work from the testing I’ve done. Perhaps the new parts just aren’t as good as the old ones!
 

Girth

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I DID read some horror stories in reviews for replacement switches. Some broke before people even got them installed. (I looked up PNs on RockAuto, then dove into reviews on Amazon). Forget what switch brand I went with, but can check later I guess.

Getting ANY good parts these days seems to be a real challenge. Is it possible to go to a dead simple mechanical valve? Simple switch to swap the signal for the gauge? Worked in my old F250..... and I do like simple things.
 

mtbadbob

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Fuel Valve replacement (I made it worse)

1984 Chevy K10. 98% stock. Dual fuel tanks. Stock Rocker switch on the dash. Fuel valve is a six port valve, (just replaced)

Back story – Filled up the left tank. Moved the rocker switch to the left tank. Fuel gauge read full.

Drove a mile down the road. The truck started to die, moved the rocker switch back to the right tank and the truck continued to run. My brain says the valve between the tanks is bad. I didn’t do any diagnostics. I just bought a new valve.

Today

I replaced the valve. (What a pain in the neck!)
Got it all put back together, started the truck and now leaks. YAHOO.

Note the trucks fuel gauge is reading ½ on the left tank. I flipped the rocker switch. No change on the fuel gauge. Back and forth a few times, no change.

Crap, now I am worse off.

I would love some recommendations on what to check please.
Are you sure that both tanks aren't 1/2 full?? Also, make sure you get the correct rocker switch, but I think the factory harness plug dictates what kind you need as the pin location is different.
 

Dmack

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Went through similar issues a couple years ago. Intermittent. Replaced the valve, twice. Turned out to be a bad switch.

On the gauge readings, 3 o'clock means grounded out, 9 o'clock means open circuit.
 

AuroraGirl

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I just watched a video on YouTube. The person replaced both. The dash switch according to the video is under 20 bucks. I think I will try that two. Just bugs me that it got worse than when I started. Keep me posted, I will do the same.
how did you replace the valve with a 6 port motorized switcher have you tried holding the switch on the tank for a few moments
original ones said DEPRESS FULLY i assume because the contact in just switching them isnt enough
 

Shawn Wheeler

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Are you sure that both tanks aren't 1/2 full?? Also, make sure you get the correct rocker switch, but I think the factory harness plug dictates what kind you need as the pin location is different.
Yes, I was out of work when I filled that tank up. I put 60 bucks of fuel in it then couldn't get to it. That fill up will forever be in my mind.

The new valve was from RockAuto, "Looks" like the one I pulled out. But who knows if the pin out is really the same.

Heading to Napa for a new rocker switch.
 

Shawn Wheeler

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how did you replace the valve with a 6 port motorized switcher have you tried holding the switch on the tank for a few moments
original ones said DEPRESS FULLY i assume because the contact in just switching them isnt enough
Yes sir. pushed it down, held it down pressing even hard "like that will matter" and said a few more bad words in the process. My wife reminded me the truck in 40 years old. Then told me I don't work like you did 40 years ago. :/ Smart A$$ woman.
 

mtbadbob

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how did you replace the valve with a 6 port motorized switcher have you tried holding the switch on the tank for a few moments
original ones said DEPRESS FULLY i assume because the contact in just switching them isnt enough
Yes, one switch stay's centered and rocks over to the tank selected but returns to center. The other, is a typical rocker that stays in position to the selected tank. As I said, the factory harness (if it's still there) dictates what switch you need as the 3 prongs on the back of the switch are in different locations. I found that out via personal experience while I was fixing the abomination the po had hacked together on my truck!
 

mtbadbob

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Yes sir. pushed it down, held it down pressing even hard "like that will matter" and said a few more bad words in the process. My wife reminded me the truck in 40 years old. Then told me I don't work like you did 40 years ago. :/ Smart A$$ wom
 

Shawn Wheeler

Junior Member
Joined
Feb 10, 2019
Posts
18
Reaction score
32
Location
Arizona
First Name
Shawn
Truck Year
1984
Truck Model
K10
Engine Size
305
Fuel Valve replacement (I made it worse)

1984 Chevy K10. 98% stock. Dual fuel tanks. Stock Rocker switch on the dash. Fuel valve is a six port valve, (just replaced)

Back story – Filled up the left tank. Moved the rocker switch to the left tank. Fuel gauge read full.

Drove a mile down the road. The truck started to die, moved the rocker switch back to the right tank and the truck continued to run. My brain says the valve between the tanks is bad. I didn’t do any diagnostics. I just bought a new valve.

Today

I replaced the valve. (What a pain in the neck!)
Got it all put back together, started the truck and now leaks. YAHOO.

Note the trucks fuel gauge is reading ½ on the left tank. I flipped the rocker switch. No change on the fuel gauge. Back and forth a few times, no change.

Crap, now I am worse off.

I would love some recommendations on what to check please.
UPDATE
I replaced the rocker switch on the dash with Napa part FS500.
Flipped the switch, gauge read full. Put it the other way, gauge read 1/2
I let it run for 15 minutes on both tanks. Never died.

I am going to call this a win.

Ended up replacing the fuel valve from Rock Auto - https://www.rockauto.com/?carcode=1030914&parttype=6276
Selector switch Napa FS500

Replacing that valve is a major PAIN. If you do this, make sure you change the hoses while you are dirty.

Thanks for all the advice.
 

mtbadbob

Full Access Member
Joined
May 9, 2021
Posts
629
Reaction score
941
Location
Montana
First Name
Bob
Truck Year
1987
Truck Model
V20
Engine Size
350
UPDATE
I replaced the rocker switch on the dash with Napa part FS500.
Flipped the switch, gauge read full. Put it the other way, gauge read 1/2
I let it run for 15 minutes on both tanks. Never died.

I am going to call this a win.

Ended up replacing the fuel valve from Rock Auto - https://www.rockauto.com/?carcode=1030914&parttype=6276
Selector switch Napa FS500

Replacing that valve is a major PAIN. If you do this, make sure you change the hoses while you are dirty.

Thanks for all the advice.
Yeah, the hoses going to the valve are short & tough to get them on & tight for sure!
 

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