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Home » Public Forums » GMCnet » [GMCnet] Exhaust manifold changing
[GMCnet] Exhaust manifold changing [message #325729] Sat, 04 November 2017 05:28 Go to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
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Senior Member
You gotta love the PO of your coach.

My exchaust manifold and/or gasket was shot, and I got a new set from
Espen. This is easy, especially on the RH side. Or so I thought. Take of
7 bolts, put new gaskets and manifold in, tighten 7 bolts, drive away happy.

http://possy.de/manifold.jpg

oops :-/

The upper one I received from Espen (which according to the parts book
is correct), the lower one was on the coach. Yeah...
--
Best regards

Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA

'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH

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Best regards

Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Exhaust manifold changing [message #325735 is a reply to message #325729] Sat, 04 November 2017 10:35 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Peer,

Here's photos of both exhaust manifolds:

http://www.gmcmhphotos.com/photos/g6894-oem-exhaust-manifolds.html

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Peer Oliver Schmidt GMC
Sent: Saturday, November 4, 2017 5:29 AM
To: gmclist@list.gmcnet.org
Subject: [GMCnet] Exhaust manifold changing

You gotta love the PO of your coach.

My exchaust manifold and/or gasket was shot, and I got a new set from Espen. This is easy, especially on the RH side. Or so I
thought. Take of 7 bolts, put new gaskets and manifold in, tighten 7 bolts, drive away happy.

http://possy.de/manifold.jpg

oops :-/

The upper one I received from Espen (which according to the parts book is correct), the lower one was on the coach. Yeah...
--
Best regards

Peer Oliver Schmidt


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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] Exhaust manifold changing [message #325741 is a reply to message #325729] Sat, 04 November 2017 11:11 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
If you don't want to change the exhaust system right now and have access to a grinder, a torch, some brazing rods, and a 2x4 plank of flat wood, you can reuse the cracked one until you find another using its part #. If the bolt holes still line up, screw the manifold down through them to the 2x4. Clean that patch stuff outta the crack area and make a v notch all along the crack. Heat the manifold in an oven to get it uniformly hot and dried out and immediately braze the notch you carved all along the crack. Put it back in the hot oven to cool a little slower, and then check it out about an hour later. Not a forever fix, but I had one last a couple of years that way (until I pulled the motor) on a small block Ford.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
Re: [GMCnet] Exhaust manifold changing [message #325745 is a reply to message #325735] Sat, 04 November 2017 11:38 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
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Senior Member
Rob Mueller schrieb/wrote
> Peer,
>
> Here's photos of both exhaust manifolds:
>
> http://www.gmcmhphotos.com/photos/g6894-oem-exhaust-manifolds.html
That corresponds to the one Espen send me. And which is the correct one
according to the parts book. My messages was really just some venting
about why oh why, do people do these shortcuts, instead of doing it right.

Terry, I'll reuse the old manifold to drive to another GMC user who will
make sure that Espen's manifold will connect to my exhaust. I've lived
with the loud exhaust for 3-4 trips now, I can live with it for one
more. And maybe my magic cement that I put into the old manifold will
hold, and the new gasket will hold as well, and everything will be quiet
again. :-)

--
Best regards

Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA

'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH


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Best regards

Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Exhaust manifold changing [message #325750 is a reply to message #325741] Sat, 04 November 2017 11:49 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Registered: May 2010
Karma: -62
Senior Member
Only thing I might add is to drill a small (1/16") hole in the ends of the
crack to prevent it traveling while you are brazing it. Slow cooling is
important. In my experience, brass works equally well as welding does. When
I am serious about saving the casting, I will do the same preparation as
brazing, but I use stainless steel rod and a tig torch and after cool the
weld affected zone with inert gas after the welding process. It displaces
the nitrogen from the surrounding air and prevents embrittelment. Old
welding trick that I learned from an O.T. (old timer). The stainless stick
rod flows very well, kinda like brass with an oxy/acetylene torch.
Jim Hupy
Salem, Or

On Nov 4, 2017 9:32 AM, "Terry" wrote:

> If you don't want to change the exhaust system right now and have access
> to a grinder, a torch, some brazing rods, and a 2x4 plank of flat wood, you
> can reuse the cracked one until you find another using its part #. If the
> bolt holes still line up, screw the manifold down through them to the 2x4.
> Clean that patch stuff outta the crack area and make a v notch all along
> the crack. Heat the manifold in an oven to get it uniformly hot and dried
> out
> and immediately braze the notch you carved all along the crack. Put it
> back in the hot oven to cool a little slower, and then check it out about an
> hour later. Not a forever fix, but I had one last a couple of years that
> way (until I pulled the motor) on a small block Ford.
> --
> Terry Kelpien
>
> ASE Master Technician
>
> 73 Glacier 260
>
> Smithfield, Va.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Exhaust manifold changing [message #325771 is a reply to message #325745] Sun, 05 November 2017 07:21 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Peer,

Re: "why oh why, do people do these shortcuts, instead of doing it right"

I Googled "GM 395792" and came up with the links below:

1968 OLDSMOBILE TORONADO RIGHT EXHAUST MANIFOLD CAST ...
www.ebay.com > ... > Car & Truck Parts > Exhaust > Exhaust Manifolds & Headers
... CAST #395752 | eBay Motors, Parts & Accessories, Car & Truck Parts | eBay! ... 395752. Warranty: No. Other Part Number: 395752,
Country/Region of ... GM ...

https://www.ebay.com/itm/1968-OLDSMOBILE-TORONADO-RIGHT-EXHAUST-MANIFOLD-CAST-395752-/121465942981

Tiny URL: http://tinyurl.com/yao8jlf6

GMPartsWiki - 395752
www.gmpartswiki.com/w/395752&book=171
MANIFOLD 65 71 425 455 rrigat1 r1 Engine 393384 Z 11 05 MANIFOLD 67 72 Tor 395752 RH 17 35 MANIFOLD 67 59 Tor 399425 LH 33 50
MANIFOLD.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwi1wvjSvqfXAhVq_IMKHQgiC5EQFg guMAE&url=http
%3A%2F%2Fwww.gmpartswiki.com%2Fw%2F395752%26book%3D171&usg=AOvVaw0CG8GMG0zZ2fU3lv50V18U

Tiny URL: http://tinyurl.com/y8cc8n53

Possibilities:

- PO replaced the engine in your GMC with one out of a 1968 Toronado?
- PO replaced a bad exhaust manifold with the repaired one on there now? BTW whoever welded it did a crap

Does the LH exhaust manifold look like the picture I posted?

From the photo of the two manifolds you posted I doubt the exhaust pipe that connects the cracked exhaust manifold to the muffler
will fit the correct exhaust manifold Espen sent you. Hopefully you will be able to have a replacement pipe fabricated in Europe. If
not it is reasonable to assume Jim K. could send you one IF the RH muffler and its location is OEM as shipped from GMC.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Peer Oliver Schmidt GMC
Sent: Saturday, November 4, 2017 11:39 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Exhaust manifold changing

Rob Mueller schrieb/wrote

Terry, I'll reuse the old manifold to drive to another GMC user who will
make sure that Espen's manifold will connect to my exhaust. I've lived
with the loud exhaust for 3-4 trips now, I can live with it for one
more. And maybe my magic cement that I put into the old manifold will
hold, and the new gasket will hold as well, and everything will be quiet
again. :-)

--
Best regards

Peer Oliver Schmidt


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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] Exhaust manifold changing [message #325772 is a reply to message #325771] Sun, 05 November 2017 07:54 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
Senior Member
Rob,

The non fitting down pipe is the main issue. If my pasteing doesn't help with the loud manifold, I'll get the down pipe amended.
--
Best regards

Peer Oliver Schmidt
'76a Eleganza II, VA
'73 Sequoia, Germany
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Best regards

Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Exhaust manifold changing [message #325773 is a reply to message #325772] Sun, 05 November 2017 08:16 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Peer,

Quite frankly I would not put the cracked manifold back on; it is releasing exhaust gasses that could cause damage because of the
increased heat.

When John and I were bringing the Kingsley back to Houston an exhaust leak started, it heated a rubber tube to the transmission oil
cooler and caused it to fail. Transmission oil got squirted on to the manifold and it caught fire.

Fortunately John grabbed one of my AFFF extinguishers, ran outside to the drivers side, got on the ground and put it out before it
did any real damage.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808



-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Peer Oliver Schmidt
Sent: Sunday, November 5, 2017 7:55 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Exhaust manifold changing

Rob,

The non fitting down pipe is the main issue. If my pasteing doesn't help with the loud manifold, I'll get the down pipe amended.
--
Best regards

Peer Oliver Schmidt
'76a Eleganza II, VA
'73 Sequoia, Germany
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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] Exhaust manifold changing [message #325774 is a reply to message #325773] Sun, 05 November 2017 09:34 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
Senior Member
Understood. It has been like that for probably 2000+MLS, so a hundred more won't make a big difference. Or so I hope. And I still hope that my work has fixed the issue. Monday afternoon will tell the outcome
--
Best regards

Peer Oliver Schmidt
'76a Eleganza II, VA
'73 Sequoia, Germany
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Best regards

Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Exhaust manifold changing [message #325775 is a reply to message #325774] Sun, 05 November 2017 09:52 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Peer,

Examine the area around the leak for signs of heat damage.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Peer Oliver Schmidt
Sent: Sunday, November 5, 2017 9:34 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Exhaust manifold changing

Understood. It has been like that for probably 2000+MLS, so a hundred more won't make a big difference. Or so I hope. And I still
hope that my work has fixed the issue. Monday afternoon will tell the outcome
--
Best regards

Peer Oliver Schmidt


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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] Exhaust manifold changing [message #325833 is a reply to message #325729] Tue, 07 November 2017 17:28 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Cinnabar has reproduction manifolds. I do not know the price but if it was me, I would probably just buy one over attempted brazing with our long term road load heat.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] Exhaust manifold changing [message #325835 is a reply to message #325833] Tue, 07 November 2017 18:28 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

I monitor eBay and as you can see from the picture I posted I have a spare set I got there for a reasonable price. I also have a
spare set for my GMC in Australia.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of John R. Lebetski
Sent: Tuesday, November 7, 2017 5:28 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Exhaust manifold changing

Cinnabar has reproduction manifolds. I do not know the price but if it was me, I would probably just buy one over attempted brazing
with our long term
road load heat.
--
John Lebetski
Woodstock, IL
77 Eleganza II


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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] Exhaust manifold changing [message #325846 is a reply to message #325835] Wed, 08 November 2017 04:19 Go to previous message
Olly Schmidt is currently offline  Olly Schmidt   United States
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
Senior Member
Just to get things straight:

I have a set of "new" manifolds. It was just a matter of the PO bringing
a non-GMC MotorHome manifold into the system, which now means a one hour
job is turning it a full day due to modifications to the exhaust.

So, thanks all for the suggestion of getting a new one. I have them
already :-) - and on Friday the coach will get it installed.

--
Best regards

Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA

'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH


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Best regards

Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
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