| fuel selector valve [message #331925] |
Thu, 10 May 2018 17:45  |
pzerkel
Messages: 212
Registered: September 2007
Location: Salisbury, IL
Karma: 0
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Senior Member |
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I has suspected I had a gas leak. I confirmed that today, and discovered it appeared to be coming from the fuel selector valve. What is the failure mode of these. After I started the coach and ran it from the main tank for a few minutes, gas kept dripping out at the valve.
I was not sure if it was the valve itself or the hoses going into it. A few years ago I replace all the rubber hose from the selector valve to the fuel pump with Gates Barricade, and all that appears to still be in good shape. The leak in my case appeared to be coming from the top connector input into the selector valve. Which is plumbed to the main (rear) tank.
What surprised me was when I took that hose off the top input connector, gas kept coming and coming from that port on the input to the selector valve. What I did as a quick fix what put a short plugged fuel hose onto that input. But of course then I could only draw fuel from the aux tank.
My question: is this normal behavior of the fuel selector valve when one input hose is disconnected, or does it mean I likely have a defective selector valve.
I inspected the hose I pulled off the input and it was pretty chewed up. But I am not sure if it just had deteriorated or I tore it up trying to get it off. Probably some of both. Ultimately I cut it back about 12 inches and got a hose barb connector and patched a new piece of Barricade in its place. That appears to have stopped the leak for now. But I know the real long term fix is to drop the tanks and replace the fuel hoses from the senders to the valve.
Again my main question is: Is this leaking from the disconnect input normal behavior of the fuel selector valve when one input hose is disconnected, or does it mean I likely have a defective selector valve?
Thank You.
Paul Zerkel
'78 Eleganza II
Salisbury IL (near Springfield)
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| Re: fuel selector valve [message #331926 is a reply to message #331925] |
Thu, 10 May 2018 18:09  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Here is the problem. If you disconnect the main tank hose at the valve with the power off, the valve is set to main tank. The hose is full of gasoline from the engine driven fuel pump all the way back to the tank. You are probably just seeing that stored gasoline draining out.
As far as leaking when running you probably have a bad connection at the valve pump or a cracked valve. There should be no pressure at the valve because it is on the input (suction) side of the fuel pump. If you have installed an electric pump then the pressure situation changes depending on where you mounted and plumbed the pump.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] fuel selector valve [message #331930 is a reply to message #331926] |
Thu, 10 May 2018 18:42 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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If the selector valve is older than 4-5 years, replaceitas the rubber
inside is deteriating from ethanal.
On Thu, May 10, 2018 at 4:09 PM, Ken Burton wrote:
> Here is the problem. If you disconnect the main tank hose at the valve
> with the power off, the valve is set to main tank. The hose is full of
> gasoline from the engine driven fuel pump all the way back to the tank.
> You are probably just seeing that stored gasoline draining out.
>
> As far as leaking when running you probably have a bad connection at the
> valve pump or a cracked valve. There should be no pressure at the valve
> because it is on the input (suction) side of the fuel pump. If you have
> installed an electric pump then the pressure situation changes depending on
> where you mounted and plumbed the pump.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: fuel selector valve [message #331951 is a reply to message #331925] |
Fri, 11 May 2018 10:23 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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What JimK said. Here's one solution:
http://www.gmcmhphotos.com/photos/g6198-cane-9-creek-rv-park-heflin-2c-al.html
That's a pair of Mr. Gasket pumps, the relay is driven by the tank switch instead of the valve which isn't used in this configuration. Mr. Gasket pumps have check valves at their output so none are needed. The supplied filter for them is junk and will leak, replace it with the Wix identical filter at install. Works fine, lasts a long time.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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