Home » Public Forums » GMCnet » Onan fuel line is very old
| Onan fuel line is very old [message #362905] |
Thu, 18 March 2021 19:19  |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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I pulled out the Onan to have a better look at it and I was scared to push it back in after I felt the fuel line, it's pretty old and hard. I don't want to touch it until I have the proper line and fittings, but of course, things are never that straightforward. Info from previous owner is that something was leaking near the carb, maybe the carb
Anyhow, it appear to have a compression fitting, but also a hose clamp, so I'm not sure how much of a stub sticking out, but it probably doesn't have a barb on it. I'll go shop for better fittings tomorrow.
Let me guess, it's not quite stock 
I have some 1/4" Goodyear Instagrip I hose, any reason not to use it? The clear stuff is nice to see gas in, but it looks delicate.
Should I also stick an inline filter back there?
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| Re: Onan fuel line is very old [message #362909 is a reply to message #362906] |
Thu, 18 March 2021 21:00  |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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RF_Burns wrote on Thu, 18 March 2021 20:02You are thinking too deep on this for me! I replaced the old hose with 1/4" barrier (ethanol resistant) hose and made sure it would loop without kinking when I closed the drawer. Its worked since 2008 for me!
One thing, I don't like the worm-gear hose clamps for fuel applications. They seem to cut into the hose, so I've been using the fuel injection hose clamps. Just me!
One thing I found makes a big difference for starting the Onan is a "Prime Switch" at the remote panel. It bypasses the control board and allows you to prime the fuel pump and fill the carb bowl with fuel before cranking. Furthermore, Holding the Prime button down while cranking and holding until the engine comes up to operating RPM before releasing, provides a better starting experience. Just my experience.
Oh, I know I'm overthinking it, I just figure as I have to change the fitting anyhow I'll see if I can get a screw-on filter to do double duty as a filter and a hose fitting. I'll have to go to NAPA tomorrow and see what they have.
I have some better clamps.
I like the idea of pre-priming the carb. I'll see if there are any spare wires run to do that, who knows, maybe it already has that feature.
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| [GMCnet] Re: Onan fuel line is very old [message #362912 is a reply to message #362909] |
Thu, 18 March 2021 21:07 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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You might want go to our web site under ONAN and look as we have most all
that is needed.
On Thu, Mar 18, 2021 at 7:00 PM Burl Vibert wrote:
> RF_Burns wrote on Thu, 18 March 2021 20:02
>> You are thinking too deep on this for me! I replaced the old hose with
> 1/4" barrier (ethanol resistant) hose and made sure it would loop without
>> kinking when I closed the drawer. Its worked since 2008 for me!
>>
>> One thing, I don't like the worm-gear hose clamps for fuel applications.
> They seem to cut into the hose, so I've been using the fuel injection
>> hose clamps. Just me!
>>
>> One thing I found makes a big difference for starting the Onan is a
> "Prime Switch" at the remote panel. It bypasses the control board and
> allows
>> you to prime the fuel pump and fill the carb bowl with fuel before
> cranking. Furthermore, Holding the Prime button down while cranking and
> holding
>> until the engine comes up to operating RPM before releasing, provides a
> better starting experience. Just my experience.
>
> Oh, I know I'm overthinking it, I just figure as I have to change the
> fitting anyhow I'll see if I can get a screw-on filter to do double duty as
> a
> filter and a hose fitting. I'll have to go to NAPA tomorrow and see what
> they have.
> I have some better clamps.
> I like the idea of pre-priming the carb. I'll see if there are any spare
> wires run to do that, who knows, maybe it already has that feature.
> --
> Burl Vibert
> Kingston, Ontario
> 1976 GMC 26 foot, don't know the model
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
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Applied/GMC
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| Re: Onan fuel line is very old [message #362914 is a reply to message #362906] |
Fri, 19 March 2021 03:05 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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I think that thing you are calling a filter is really an electric controlled valve energized when the electric fuel pimp is running.. Some people have removed them. I like to leave them installed for reasons that I will explain later if necessary.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Onan fuel line is very old [message #362915 is a reply to message #362905] |
Fri, 19 March 2021 08:46 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Drawer to pump inlet I used Tygon ( no fuel cut off solenoid). Pump to carb I used Applied’s pre made braided unit Be aware that there may be 2 different sized 90 fittings at pump outlets used by Onan so you may need a new 90 to thread to the Applied hose. I made Jim aware of this and they sent me correct 90. Not sure if this was and early vs late production thing or what but be aware.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan fuel line is very old [message #362916 is a reply to message #362914] |
Fri, 19 March 2021 09:22 |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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Ken Burton wrote on Fri, 19 March 2021 03:05I think that thing you are calling a filter is really an electric controlled valve energized when the electric fuel pimp is running.. Some people have removed them. I like to leave them installed for reasons that I will explain later if necessary.
I know it's a shut-off valve, what I want to do is remove the compression fitting going into it and replace it with a filter. The Onan filter has a 1/4" barb at inlet and 1/8" pipe thread at the other end.
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| Re: Onan fuel line is very old [message #362917 is a reply to message #362916] |
Fri, 19 March 2021 13:10 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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OK. It was a misunderstanding on my part. When I saw the picture of the valve you posted I asumed you were thinking that valve was a filter. I hope you also realize that there is a filter built in to the bottom of the fuel pump. NAPA has replacements with a new gasket for around $$10.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Onan fuel line is very old [message #362923 is a reply to message #362917] |
Fri, 19 March 2021 20:17 |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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Ken Burton wrote on Fri, 19 March 2021 13:10OK. It was a misunderstanding on my part. When I saw the picture of the valve you posted I asumed you were thinking that valve was a filter. I hope you also realize that there is a filter built in to the bottom of the fuel pump. NAPA has replacements with a new gasket for around $$10.
I didn't know about the filter in the fuel pump. Do you have the NAPA number? In that case I won't worry about it unless there's a problem.
I assume once I remove the line from the lower fitting that gas will start pouring out? (so I'll be ready with the new line)
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| Re: Onan fuel line is very old [message #362925 is a reply to message #362923] |
Sat, 20 March 2021 00:44 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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That fuel pump was made by Bendix and the company has been bought and sold several times and changed names many times. NAPA sold and probably still sells then under their brand name. This pump is used on many, many different things including the boost pump on my airplane. The filters at NAPA come on a card designed to hang on a peg for display. The last time I bought one was many years ago. I just walked in and removed it from the peg and paid for it. Sorry I do not know the number. To access it in the pump, turn the big nut on the bottom of the pump less than 1/8 turn. The filter, cap, and reusable gasket will fall out. Most have a cleanable fine screen filter and a few have a paper filter. It is easy to get to it with the drawer all the way out and using one box end wrench. I check mine every few years but I have never found much inside it.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
[Updated on: Sat, 20 March 2021 00:55] Report message to a moderator |
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| [GMCnet] Re: Onan fuel line is very old [message #362928 is a reply to message #362926] |
Sat, 20 March 2021 11:49 |
Len Novak
Messages: 676
Registered: February 2004
Location: Las Vegas, NV
Karma: -3
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I pulled mine apart to clean it. Something about if it is not broke don’t
fix it comes to mind in my case. Nothing in the screen.
On Fri, Mar 19, 2021 at 22:58 Ken Burton wrote:
> I reworded some of this posting and for emailers that do not see updates
> you might want to look here for the updated version
>
> http://www.gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=362925&rid=12#msg_362925
>
>
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
> _______________________________________________
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*Len and Pat Novak*
*1978 GMC Kingsley*
*The Beast II with dash lights that work and labels you can see!*
*Las Vegas, NV* new email: B52sRule@Gmail.com
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
www.bdub.net/novak/
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Len and Pat Novak
1978 GMC Kingsley
The Beast II with dash lights that work and labels you can see!
Las Vegas, NV new email: B52sRule@Gmail.com
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
www.bdub.net/novak/
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| [GMCnet] Re: Onan fuel line is very old [message #362929 is a reply to message #362928] |
Sat, 20 March 2021 12:19 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Part of the reason for that filter nearly always staying clean is that it's
source of fuel is a stand pipe in the rear tank that only goes part way to
the bottom of the tank. That way, you can not dry camp and run completely
out of fuel running the Onan. Secondary benefit being that it does not pick
up all the crap sitting on the bottom of the tank.
That 3/4 feature is mostly only on GMC built coaches. Coachman, and
perhaps some others just put a "T" fitting in the hose from the rear tank
so they wouldn't have to drop the rear tank to hook up the Onan fuel line,
as they used Transmodes for their coaches.
Jim Hupy
Salem,Oregon
On Sat, Mar 20, 2021, 9:50 AM Len Len wrote:
> I pulled mine apart to clean it. Something about if it is not broke don’t
> fix it comes to mind in my case. Nothing in the screen.
>
> On Fri, Mar 19, 2021 at 22:58 Ken Burton wrote:
>
>> I reworded some of this posting and for emailers that do not see updates
>> you might want to look here for the updated version
>>
>>
> http://www.gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=362925&rid=12#msg_362925
>>
>>
>> --
>> Ken Burton - N9KB
>> 76 Palm Beach
>> Hebron, Indiana
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>>
> --
>
> *Len and Pat Novak*
>
> *1978 GMC Kingsley*
>
> *The Beast II with dash lights that work and labels you can see!*
>
> *Las Vegas, NV* new email: B52sRule@Gmail.com
>
> http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
>
>
>
> www.bdub.net/novak/
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
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| Re: Onan fuel line is very old [message #362997 is a reply to message #362905] |
Tue, 23 March 2021 18:44 |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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I got the new fuel line in and trying to start it. I disconnected the wire to the starter and can hear the fuel pump clicking/thumping (reminded me of my old MG Midget), but I didn't get any gas out of the loosened screw at the bottom of the carb. Upon investigation I replaced a section of wire with 2 patches in it going to the fuel-cutoff solenoid. Now I'm getting voltage at the solenoid valve, but I can't hear or feel a click when touching the wires together and still no gas.
Looks to me like the solenoid valve is stuck closed.
On a brighter note, I got the lights all working, replaced the blown sealed-beams with Bosch H4 lamp housings I already had. I had to weld on 3 tabs that were broken off the headlight trim rings. Just waiting for new screws for the headlight housing trim to finish it up.
H4 lights are so much better than sealed beams.
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| Re: Onan fuel line is very old [message #362999 is a reply to message #362905] |
Tue, 23 March 2021 19:16 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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If the H4 Amp draw is much higher than stock, lights may start to cycle off after a while when the dash breaker switch starts to do it’s job. I say this because you don’t mention a relay loom kit.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan fuel line is very old [message #363000 is a reply to message #362999] |
Tue, 23 March 2021 19:26 |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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JohnL455 wrote on Tue, 23 March 2021 19:16If the H4 Amp draw is much higher than stock, lights may start to cycle off after a while when the dash breaker switch starts to do it’s job. I say this because you don’t mention a relay loom kit.
I just have regular bulbs in there, I think 55 watt.
Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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| [GMCnet] Re: Onan fuel line is very old [message #363001 is a reply to message #363000] |
Tue, 23 March 2021 19:35 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Still on the Onan gas line. Just for grins and giggles, blow some air back
through your new hose, just to verify that you actually have a fuel level
high enough in the rear tank to cover up the end of the hose. The pump will
not account for a low fuel level in the tank. I don't care what your gage
says.
Jim Hupy
Salem, Oregon
On Tue, Mar 23, 2021, 5:26 PM Burl Vibert wrote:
> JohnL455 wrote on Tue, 23 March 2021 19:16
>> If the H4 Amp draw is much higher than stock, lights may start to cycle
> off after a while when the dash breaker switch starts to do it’s job. I
>> say this because you don’t mention a relay loom kit.
>
> I just have regular bulbs in there, I think 55 watt.
>
> --
> Burl Vibert
> Kingston, Ontario
> 1976 GMC 26 foot, don't know the model
> _______________________________________________
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| Re: [GMCnet] Re: Onan fuel line is very old [message #363003 is a reply to message #363001] |
Tue, 23 March 2021 21:24 |
blur911
Messages: 166
Registered: December 2020
Location: Kingston, Ontario
Karma: 4
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Yeah, still poking away at the generator in between other jobs. Anyhow, while cranking it over found out it also needs a muffler.
Good point about the fuel level. I'll probably leave it until I get more fuel, it's a backburner project anyway.
What I would like to know if what is the normal sounds to hear when priming the system? I got the fuel pump thumping/ticking, but never felt/heard the solenoid valve click. Is the pump supposed to stop thumping once it reaches pressure?
James Hupy wrote on Tue, 23 March 2021 19:35Still on the Onan gas line. Just for grins and giggles, blow some air back
through your new hose, just to verify that you actually have a fuel level
high enough in the rear tank to cover up the end of the hose. The pump will
not account for a low fuel level in the tank. I don't care what your gage
says.
Jim Hupy
Salem, Oregon
On Tue, Mar 23, 2021, 5:26 PM Burl Vibert wrote:
> JohnL455 wrote on Tue, 23 March 2021 19:16
>> If the H4 Amp draw is much higher than stock, lights may start to cycle
> off after a while when the dash breaker switch starts to do it’s job. I
>> say this because you don’t mention a relay loom kit.
>
> I just have regular bulbs in there, I think 55 watt.
>
> --
> Burl Vibert
> Kingston, Ontario
> 1976 GMC 26 foot, don't know the model
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
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Burl Vibert
Kingston, Ontario
1976 GMC 26 foot, Sheridan reno, don't know original model but we call her Roxie
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