This indicates fuel switching valve not sealing correct? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

weider1717 · 12-25-2015, 08:44 PM

While installing 2 new tanks on my 87 I first installed the right side tank.

now my switching valve seems to stick it takes several times flipping the switch and playing with it to get it to switch. Thats a known issue already.

However, I faintly got ti swapped to the side with the new tank and a little gas in it so I started it up.

noticed gas running out of the fuel line on the LEFT side which didn't currently have a tank installed..

I am not sure which is why I am asking but I don't see why fuel would be coming out of that line other than possibly that switching valve is not SEATING correctly?

am I correct on this? that line on the left side was pumping a little gas and also build pressure on it when you capped it with your thumb.

thanks for any help. Had thought I might not replace that switching valve since the right tank hadn't worked since like 2001 due to bad fuel pump and with all new tanks and pumps maybe with excersie that valve might be ok but if I am right on this I may need to go ahead and replace it.

**hatzie** · 12-26-2015, 01:20 PM

It does sound like the valve is leaking. I'd replace it.

weider1717 · 12-26-2015, 10:17 PM

Thanks, I didn't think it should be doing that and only culprit is that dang valve.

12-25-2015, 08:44 PM	#1
weider1717 Registered User Join Date: Apr 2011 Location: greenville sc Posts: 558	This indicates fuel switching valve not sealing correct? While installing 2 new tanks on my 87 I first installed the right side tank. now my switching valve seems to stick it takes several times flipping the switch and playing with it to get it to switch. Thats a known issue already. However, I faintly got ti swapped to the side with the new tank and a little gas in it so I started it up. noticed gas running out of the fuel line on the LEFT side which didn't currently have a tank installed.. I am not sure which is why I am asking but I don't see why fuel would be coming out of that line other than possibly that switching valve is not SEATING correctly? am I correct on this? that line on the left side was pumping a little gas and also build pressure on it when you capped it with your thumb. thanks for any help. Had thought I might not replace that switching valve since the right tank hadn't worked since like 2001 due to bad fuel pump and with all new tanks and pumps maybe with excersie that valve might be ok but if I am right on this I may need to go ahead and replace it.

12-26-2015, 01:20 PM	#2
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: This indicates fuel switching valve not sealing correct? It does sound like the valve is leaking. I'd replace it. __________________ 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.

12-26-2015, 10:17 PM	#3
weider1717 Registered User Join Date: Apr 2011 Location: greenville sc Posts: 558	Re: This indicates fuel switching valve not sealing correct? Thanks, I didn't think it should be doing that and only culprit is that dang valve.



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