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Left exhaust manifold donut gasket [message #283483] Wed, 29 July 2015 18:17 Go to next message
MikeT   United States
Messages: 225
Registered: November 2009
Location: Marine City, Michigan
Karma: 0
Senior Member
Hello, I'm 800 miles from home in New England with a big left side donut gasket leak. Has anyone ever changed their donut without removing the exhaust manifold. I have a donut but don't want to risk breaking manifold bolts that were last removed over 5 years ago. hopefully the exhaust flange bolts don't break.

Also, is there a fuel filter for the onan 6000? Having fuel issues with tanks verified more then half full. I see the fuel pump and what I think is a check valve but no fuel filter.

Thanks


Mike Thomas Marine City, MI 77 ex Palm Beach

[Updated on: Wed, 29 July 2015 18:18]

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Re: [GMCnet] Left exhaust manifold donut gasket [message #283486 is a reply to message #283483] Wed, 29 July 2015 18:27 Go to previous messageGo to next message
Kingsley Coach is currently offline  Kingsley Coach   United States
Messages: 2691
Registered: March 2009
Location: Nova Scotia Canada
Karma: -34
Senior Member
Don't take the manifold off!!
Loosen the bolts at the exhaust/manifold joint and insert the donut . That
having been said, get a good fitting box end wrench or a 6point socket and
a can of good penetrating fluid....soak the bolt very well
If you break a bolt you'll need vice grips and a source of heat to remove
the stud. It can be replaced with 'ready rod' until you get home .
Others will likely add more to my answer...or have a different answer

Mike in NS

On Wed, Jul 29, 2015 at 8:17 PM, Thomas Mike wrote:

> Hello, I'm 800 miles from home in New England with big left side donut
> gasket leak. Has anyone ever changed their donut without removing the
> exhaust
> manifold. I have a donut but don't want to risk breaking manifold bolts
> that were last removed over 5 years ago. Hope the exhaust flange bolts don't
> break.
>
> Also, is there a fuel filter for the onan 6000? Having fuel issues with
> tanks verified more then half full. I see the fuel pump and what I think is
> a
> check valve but no fuel filter.
>
> Thanks
> --
> Mike Thomas
> Troy, MI
> 77 ex Palm Beach, 77 Royale (rear bath)
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Michael Beaton
1977 Kingsley 26-11
1977 Eleganza II 26-3
Antigonish, NS

Life is too short to hold a grudge; slash some tires and call it even !
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Re: [GMCnet] Left exhaust manifold donut gasket [message #283490 is a reply to message #283483] Wed, 29 July 2015 18:39 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
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Registered: January 2004
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Mike,
You DO NOT have to remove the exhaust manifold from the engine to change the donut out. Spray the bolts or studs at the exhaust manifold outlet with PB Blaster or similar and the remove them. The exhaust system will drop down enough to replace the donut. Put back together and drive on.

If you have the original Onan fuel pump the filter is in the bottom which will unscrew 1/4 to 1/2 turn, it has a screen inside and a rubber o-ring as a seal.

J.R. Wright
GMC Great Laker MHC
GMC Eastern States
GMCGL Tech Editor
GMCMHI
78 GMC Buskirk 30’ Stretch
1975 GMC Avion (Under Reconstruction)
Michigan

> On Jul 29, 2015, at 7:17 PM, Thomas Mike wrote:
>
> Hello, I'm 800 miles from home in New England with big left side donut gasket leak. Has anyone ever changed their donut without removing the exhaust
> manifold. I have a donut but don't want to risk breaking manifold bolts that were last removed over 5 years ago. Hope the exhaust flange bolts don't
> break.
>
> Also, is there a fuel filter for the onan 6000? Having fuel issues with tanks verified more then half full. I see the fuel pump and what I think is a
> check valve but no fuel filter.
>
> Thanks
> --
> Mike Thomas
> Troy, MI
> 77 ex Palm Beach, 77 Royale (rear bath)
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: [GMCnet] Left exhaust manifold donut gasket [message #283492 is a reply to message #283490] Wed, 29 July 2015 18:58 Go to previous messageGo to next message
Dennis S is currently offline  Dennis S   United States
Messages: 3046
Registered: November 2005
Karma: 2
Senior Member
Mike
In my experience the donuts needed to be rotated and also tighten the three studs progressively to achieve a good seal.

Dennis

powerjon wrote on Wed, 29 July 2015 18:39
Mike,
You DO NOT have to remove the exhaust manifold from the engine to change the donut out. Spray the bolts or studs at the exhaust manifold outlet with PB Blaster or similar and the remove them. The exhaust system will drop down enough to replace the donut. Put back together and drive on.

If you have the original Onan fuel pump the filter is in the bottom which will unscrew 1/4 to 1/2 turn, it has a screen inside and a rubber o-ring as a seal.

J.R. Wright
GMC Great Laker MHC
GMC Eastern States
GMCGL Tech Editor
GMCMHI
78 GMC Buskirk 30' Stretch
1975 GMC Avion (Under Reconstruction)
Michigan

> On Jul 29, 2015, at 7:17 PM, Thomas Mike wrote:
>
> Hello, I'm 800 miles from home in New England with big left side donut gasket leak. Has anyone ever changed their donut without removing the exhaust
> manifold. I have a donut but don't want to risk breaking manifold bolts that were last removed over 5 years ago. Hope the exhaust flange bolts don't
> break.
>
> Also, is there a fuel filter for the onan 6000? Having fuel issues with tanks verified more then half full. I see the fuel pump and what I think is a
> check valve but no fuel filter.
>
> Thanks
> --
> Mike Thomas
> Troy, MI
> 77 ex Palm Beach, 77 Royale (rear bath)
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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Dennis S
73 Painted Desert 230
Memphis TN Metro
Re: [GMCnet] Left exhaust manifold donut gasket [message #283502 is a reply to message #283492] Wed, 29 July 2015 23:49 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Location: Sydney, Australia
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Dennis,

Please explain.

Regards,
Rob M.


-----Original Message-----
From: Dennis Sexton

Mike
In my experience THE DONUTS NEEDED TO BE ROTATED and also tighten the three studs progressively to achieve a good seal.

Dennis




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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Left exhaust manifold donut gasket [message #283506 is a reply to message #283502] Thu, 30 July 2015 00:32 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Registered: July 2006
Location: Belmont, CA
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Senior Member
​I think Dennis was thinking of a header donuts.​

On Wed, Jul 29, 2015 at 9:49 PM, Robert Mueller
wrote:

> Dennis,
>
> Please explain.
>
> Regards,
> Rob M.
>
>
> -----Original Message-----
> From: Dennis Sexton
>
> Mike
> In my experience THE DONUTS NEEDED TO BE ROTATED and also tighten the
> three studs progressively to achieve a good seal.
>
> Dennis
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



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Applied/GMC, Fremont,CA
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jimk@appliedairfilters.com
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Re: [GMCnet] Left exhaust manifold donut gasket [message #283507 is a reply to message #283502] Thu, 30 July 2015 01:32 Go to previous messageGo to next message
Dennis S is currently offline  Dennis S   United States
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Registered: November 2005
Karma: 2
Senior Member
Rob

The exhaust donuts (from NAPA) that I installed did not seal well but when I rotated them -- there was a "sweet spot" where they fit best between the manifold and the flare of the down pipe. The three attachment nuts should then be started and each brought down progressively (each a little at a time) to ensure they pull up the flare to the manifold.

Hopefully this is more clear.

Dennis

USAussie wrote on Wed, 29 July 2015 23:49
Dennis,

Please explain.

Regards,
Rob M.


-----Original Message-----
From: Dennis Sexton

Mike
In my experience THE DONUTS NEEDED TO BE ROTATED and also tighten the three studs progressively to achieve a good seal.

Dennis




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Dennis S
73 Painted Desert 230
Memphis TN Metro
Re: [GMCnet] Left exhaust manifold donut gasket [message #283519 is a reply to message #283507] Thu, 30 July 2015 07:33 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Dennis,

Thanks, I understand.

I discovered that there are different donuts available. Some have a straight flat surface that contacts exhaust pipe and some have a
rounded surface. I prefer the rounded surface type. I bought them at Car Quest. Unfortunately I don't have any here in Sydney so I
don't know what the part number is.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Dennis Sexton

Rob

The exhaust donuts (from NAPA) that I installed did not seal well but when I rotated them -- there was a "sweet spot" where they fit
best between the manifold and the flare of the down pipe. The three attachment nuts should then be started and each brought down
progressively (each a little at a time) to ensure they pull up the flare to the manifold.

Hopefully this is more clear.

Dennis




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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Left exhaust manifold donut gasket [message #283524 is a reply to message #283483] Thu, 30 July 2015 08:51 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
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Registered: October 2010
Location: St. Cloud, MN
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Senior Member
Let us know how it turns out, The bolts will either come out or break... Lucky for me, Mine came out easily. That is the only thing that might make this a simple repair or a real pain.

I found the exhaust doughnuts hard to come by, and all parts shops in town needed to order them in. So it is good you have a spare Again, you should not need to remove the exhaust manifold, and if you remove the wheel liner, you will have easy access.





Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Left exhaust manifold donut gasket [message #283540 is a reply to message #283524] Thu, 30 July 2015 13:03 Go to previous messageGo to next message
MikeT   United States
Messages: 225
Registered: November 2009
Location: Marine City, Michigan
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Senior Member
Thanks to all for my donut change Success.

I drive without the inner wheel liners so a clear shot. Although I went through the engine compartment for the left side donut. I lubed up real good with PB blaster last night. Gave it another lube this morning. Crossed my fingers and closed my eyes as I started to back off flange bolts. Both came off pretty good without much struggle. Plenty of room to put new donut in after loosening/removing two bolts ;I only have two bolts not three on the 77 455. The donut I removed was stripped bare of insulation material. Much quieter now with the exception of a smaller leak front of left manifold.

The Donut I used was the rounded type. Bought at a Michigan auto parts store a few months back for $17.

Without all your advice, I probably would not have attempted this on the road and put up with the extra noise all the way home.

Thanks again


Mike Thomas Marine City, MI 77 ex Palm Beach
Re: Left exhaust manifold donut gasket [message #283543 is a reply to message #283483] Thu, 30 July 2015 13:17 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
glad to hear, and from my recent experience, better to tackle it now, even on the road.

I had one exhaust manifold gasket go bad, and i put alot of miles on it, without it getting much worse. The last one I had fail, I put about 100 miles on and it got way worse, to a point I was worried about other issues, and I was forced to change it on the road, when it was HOT! I had the opportunity to change it when it was cold at the start of the day, but thought I could make it home.


Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Left exhaust manifold donut gasket [message #283559 is a reply to message #283540] Thu, 30 July 2015 17:29 Go to previous message
Dennis S is currently offline  Dennis S   United States
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Registered: November 2005
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Senior Member
Mike

Well done -- thanks for the feedback.

Correction -- Somehow I kept saying three studs but as you pointed out there are only two.

Dennis


MikeT wrote on Thu, 30 July 2015 13:03
Thanks to all for my donut change Success.

I drive without the inner wheel liners so a clear shot. Although I went through the engine compartment for the left side donut. I lubed up real good with PB blaster last night. Gave it another lube this morning. Crossed my fingers and closed my eyes as I started to back off flange bolts. Both came off pretty good without much struggle. Plenty of room to put new donut in after loosening/removing two bolts ;I only have two bolts not three on the 77 455. The donut I removed was stripped bare of insulation material. Much quieter now with the exception of a smaller leak front of left manifold.

The Donut I used was the rounded type. Bought at a Michigan auto parts store a few months back for $17.

Without all your advice, I probably would not have attempted this on the road and put up with the extra noise all the way home.

Thanks again



Dennis S
73 Painted Desert 230
Memphis TN Metro
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