Can you ID this? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

raidmagic · 11-26-2019, 02:50 PM

1980 1/2 ton. Just got the new engine and trans in and now have a fuel leak. It's coming off this little part. Almost looks like a pressure switch to me. No idea what it is or how to stop it from leaking.
Help?

44th Miss Inf · 11-26-2019, 02:59 PM

Looks like your switching valve for dual tanks from what I can see on my phone

Dead Parrot · 11-26-2019, 03:45 PM

Looks like a dirty version of this: https://www.amazon.com/SWITCHING-SEL.../dp/B0758RJ1KN

I would replace all three hoses first to make sure it isn't a rotted hose. If one or more is OEM, they are definitely EOL.

If it is a 6 port instead of a three port, replacements are pretty much unobtainium. The normal fix is a newer motorized version but that takes some wiring modifications.

raidmagic · 11-26-2019, 03:55 PM

It is my switching port I'm focused on the black tube that looks torn. That is where fuel is leaking out but it goes nowhere.

**hatzie** · 11-26-2019, 05:24 PM

Quote:

Originally Posted by raidmagic

It is my switching port I'm focused on the black tube that looks torn. That is where fuel is leaking out but it goes nowhere.

If it's leaking there then the valve is borked. That's the air vent for the valve.

raidmagic · 11-26-2019, 05:33 PM

Quote:

Originally Posted by hatzie

If it's leaking there then the valve is borked. That's the air vent for the valve.

Well that's not what I wanted to hear.

OK I have 81 parts truck. They are different valves, can I use it? The plug is different and the lines look a little different.

swissarmychainsaw · 11-26-2019, 07:52 PM

Are you running dual tanks on the 80?
If not, ditch it.
But yeah, I agree with replacing the hoses.

If you ARE running dual tanks, why not put a new one in there?

**hatzie** · 11-26-2019, 08:11 PM

The 81-91 motorized valves are more reliable than the old solenoid system and a heckuva lot easier to source parts for. They're tedious but not difficult to move if you have a reasonably complete parts truck.

Mark the disconnection points with a sharpie and painters tape. LH tank is the driver side RH tank is the passenger side in the US.
I wouldn't hesitate to liberate the 81-86 NL2 tank switch harness and valve from your 1981. Be super careful to make sure the supply and return lines are correctly oriented. You can end up with fuel returning to the tank not in use if you're not careful.

The 1981 NL2 harness will be in two pieces.

Inside the cab has terminations in the engine bay just past the firewall grommet, at the fuse panel, at the ground buss bar above the E-Brake, and at the switch. In my experience usually the switch is shot and it's different from the 73-80 switch. If the valve doesn't spring to life when you plug everything in replace the switch with an 87-91 TBI switch... NOTE!!! there are locator bumps on the switch terminals that differ between the TBI and regular switch. You can safely modify the plug to fit the TBI switch.
Under the cab the gauge wire from the firewall will have a rubber molded disconnect on the RH frame rail and the valve has a 6 position Weatherpak tower plug. The senders run from the tanks to the valve plug and they use the same molded plugs as the 73-80 senders so disconnect them and move them to the older truck.

raidmagic · 11-26-2019, 08:52 PM

Ok. So how about this. I need to get the truck on the road. The drivers tank hadn't worked since I got the truck. Bypassing it is doable? Thoughts?

**hatzie** · 11-26-2019, 09:46 PM

Two sections of hose to run between the supply and return of the tank you're going to use and the main supply and return.

You can pick either tank.

SunSoaked · 11-26-2019, 10:37 PM

Quote:

Originally Posted by hatzie

borked.

Love that description! Hatzie gets the award for quote of the month. Borked! Lol. The first time I heard this was during the Kavanaugh hearings.

raidmagic · 11-27-2019, 10:39 PM

Quote:

Originally Posted by SunSoaked

Love that description! Hatzie gets the award for quote of the month. Borked! Lol. The first time I heard this was during the Kavanaugh hearings.

;lol yeah that was pretty good.

**hatzie** · 11-28-2019, 02:30 PM

Quote:

Originally Posted by SunSoaked

Love that description! Hatzie gets the award for quote of the month. Borked! Lol. The first time I heard this was during the Kavanaugh hearings.

I thought Borked came from this guy...

http://www.youtube.com/watch?v=DDHyXxITass

11-26-2019, 02:50 PM	#1
raidmagic Registered User Join Date: Jan 2015 Location: Tampa, Fl. Posts: 426	Can you ID this? 1980 1/2 ton. Just got the new engine and trans in and now have a fuel leak. It's coming off this little part. Almost looks like a pressure switch to me. No idea what it is or how to stop it from leaking. Help? __________________ 1965 C-10 1/2 ton shortbed part time daily driver 1980 C-10 1/2 ton shortbed project

11-26-2019, 02:59 PM	#2
44th Miss Inf Registered User Join Date: Sep 2002 Location: Liberty, Mississippi Posts: 673	Re: Can you ID this? Looks like your switching valve for dual tanks from what I can see on my phone

11-26-2019, 03:45 PM	#3
Dead Parrot Registered User Join Date: Aug 2012 Location: Oklahoma City, OK Posts: 2,627	Re: Can you ID this? Looks like a dirty version of this: https://www.amazon.com/SWITCHING-SEL.../dp/B0758RJ1KN I would replace all three hoses first to make sure it isn't a rotted hose. If one or more is OEM, they are definitely EOL. If it is a 6 port instead of a three port, replacements are pretty much unobtainium. The normal fix is a newer motorized version but that takes some wiring modifications.

11-26-2019, 03:55 PM	#4
raidmagic Registered User Join Date: Jan 2015 Location: Tampa, Fl. Posts: 426	Re: Can you ID this? It is my switching port I'm focused on the black tube that looks torn. That is where fuel is leaking out but it goes nowhere. __________________ 1965 C-10 1/2 ton shortbed part time daily driver 1980 C-10 1/2 ton shortbed project

11-26-2019, 07:52 PM	#7
swissarmychainsaw Registered User Join Date: Jun 2009 Location: san francisco, ca (east bay) Posts: 674	Re: Can you ID this? Are you running dual tanks on the 80? If not, ditch it. But yeah, I agree with replacing the hoses. If you ARE running dual tanks, why not put a new one in there?

11-26-2019, 08:11 PM	#8
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Can you ID this? The 81-91 motorized valves are more reliable than the old solenoid system and a heckuva lot easier to source parts for. They're tedious but not difficult to move if you have a reasonably complete parts truck. Mark the disconnection points with a sharpie and painters tape. LH tank is the driver side RH tank is the passenger side in the US. I wouldn't hesitate to liberate the 81-86 NL2 tank switch harness and valve from your 1981. Be super careful to make sure the supply and return lines are correctly oriented. You can end up with fuel returning to the tank not in use if you're not careful. The 1981 NL2 harness will be in two pieces. Inside the cab has terminations in the engine bay just past the firewall grommet, at the fuse panel, at the ground buss bar above the E-Brake, and at the switch. In my experience usually the switch is shot and it's different from the 73-80 switch. If the valve doesn't spring to life when you plug everything in replace the switch with an 87-91 TBI switch... NOTE!!! there are locator bumps on the switch terminals that differ between the TBI and regular switch. You can safely modify the plug to fit the TBI switch. Under the cab the gauge wire from the firewall will have a rubber molded disconnect on the RH frame rail and the valve has a 6 position Weatherpak tower plug. The senders run from the tanks to the valve plug and they use the same molded plugs as the 73-80 senders so disconnect them and move them to the older truck. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

11-26-2019, 08:52 PM	#9
raidmagic Registered User Join Date: Jan 2015 Location: Tampa, Fl. Posts: 426	Re: Can you ID this? Ok. So how about this. I need to get the truck on the road. The drivers tank hadn't worked since I got the truck. Bypassing it is doable? Thoughts? __________________ 1965 C-10 1/2 ton shortbed part time daily driver 1980 C-10 1/2 ton shortbed project

11-26-2019, 09:46 PM	#10
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Can you ID this? Two sections of hose to run between the supply and return of the tank you're going to use and the main supply and return. You can pick either tank. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.