| Thorley Header leaking at manifold [message #100992] |
Sat, 25 September 2010 19:30  |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Hi all,
Hope those who are at Duquoin are having a great time! Wish I was able to attend.
My RH Thorley is leaking at the forward tube. When I installed the headers I used Remflex gaskets. When I received the gaskets they were damaged on one end but only at the bolt hole. I was told it would be okay and I agreed. Well 1200 miles later it started to leak. So today I removed the bolts and pulled the header far enough back to remove the gasket. Sure enough I could see evidence of a leak at the damaged gasket end. No problem I will install the Thorley gasket that came with the headers. The old gasket came off cleanly on the header side but left some gasket material on the head.I was able to clean off the gasket material easily with out removing the header. After cleaning I installed the new gasket, torqued the bolts to 45 lbft leaving the center bolt hand tight.
I then fired it up and to my dismay I still have a leak and it sounds like it is still at the forward tube. There is no external evidence of a leak that I can see and I can't feel any exhaust when I "carefully" feel around the flange while running.
My next step is to remove and inspect the header. Has anyone with Thorley's had a similar experience? Any suggestions?
ALSO when I remove the header I'll need to replace the collector gasket. Does anyone know if you can buy these collector/doughnut gaskets locally?
Jon
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: [GMCnet] Thorley Header leaking at manifold [message #100993 is a reply to message #100992] |
Sat, 25 September 2010 20:03  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Jon,
Torque of 45 lbs may be too much. I don't have headers on my coach now -- but put them on a previous coach and seem to remember it was about the same as cast iron manifolds -- like 24 ft lbs. And I assume you used a tightening sequence and tightened in increments.
Heater hose makes a good stethescope -- be careful not to hold it in your ear, only near -- and move it along the header and exhaust area to determine where the leak is.
If you need a Thorley header gasket I have some here. I thought the collector gasket was reusable -- unless you perhaps used a sealant.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Jon Payne <embrep@sbcglobal.net>
To: gmclist@temp.gmcnet.org
Sent: Sat, Sep 25, 2010 7:30 pm
Subject: [GMCnet] Thorley Header leaking at manifold
Hi all,
Hope those who are at Duquoin are having a great time! Wish I was able to
ttend.
My RH Thorley is leaking at the forward tube. When I installed the headers I
sed Remflex gaskets. When I received the gaskets they were damaged on one end
ut only at the bolt hole. I was told it would be okay and I agreed. Well 1200
iles later it started to leak. So today I removed the bolts and pulled the
eader far enough back to remove the gasket. Sure enough I could see evidence of
leak at the damaged gasket end. No problem I will install the Thorley gasket
hat came with the headers. The old gasket came off cleanly on the header side
ut left some gasket material on the head.I was able to clean off the gasket
aterial easily with out removing the header. After cleaning I installed the
ew gasket, torqued the bolts to 45 lbft leaving the center bolt hand tight.
I then fired it up and to my dismay I still have a leak and it sounds like it is
till at the forward tube. There is no external evidence of a leak that I can
ee and I can't feel any exhaust when I "carefully" feel around the flange while
unning.
My next step is to remove and inspect the header. Has anyone with Thorley's had
similar experience? Any suggestions?
ALSO when I remove the header I'll need to replace the collector gasket. Does
nyone know if you can buy these collector/doughnut gaskets locally?
Jon
-
on Payne
6 Palm Beach
estfield,IN
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] Thorley Header leaking at manifold [message #100995 is a reply to message #100993] |
Sat, 25 September 2010 20:20 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Senior Member |
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Thanks Dennis for the tip, I'll try that.
Regarding the torque that is per the instructions from Thorley. Besides the LH side has no leaks and I torqued them to 45. Regarding the collector gasket I too think they should be reusable but knowing my luck I'll need to replace it for some reason.
Thanks again Dennis!
JP
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: Thorley Header leaking at manifold [message #100996 is a reply to message #100992] |
Sat, 25 September 2010 20:23 |
bernie
Messages: 46
Registered: February 2008
Location: Montreal
Karma: 0
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Jon;
I have the exact same problem...I first replaced the gasket with the Remflex one, but the leak is still there...Next thing to do will be to remove and inspect the Thorley header. I think the P.O
told me he had to resolder something on the header in the past...We'll see..
Let us know what you find...I'm not sure I'll have time to work on mine before winter storage...
Bernard
GMC Transmode 1977
Montreal,Canada
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101000 is a reply to message #100997] |
Sat, 25 September 2010 21:42 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Thanks Guys! I'm really bummed out having to mess with this exhaust leak. I hate having to redo something especially considering the cost of these headers. I recently had to replace my AC compressor again because the first rebuilt one leaked oil every.
Anyway I'll yank the header off tomorrow and report what I find. I'm now thinking that the problem is with the header. I just hope what every is wrong with it will be obvious.
I'll post the results hopefully tomorrow.
JP
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101014 is a reply to message #101000] |
Sat, 25 September 2010 23:11 |
jtblank
Messages: 237
Registered: June 2007
Location: Tulare, CA
Karma: 1
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Jon,
Be sure to check where the header tube is welded to the flange that bolts to the head. I had a similar experience years ago on some tri-y headers on my '65 Mustang GT, there was a tiny little crack at the tube to flange and actually found it by looking closely at the header and found a little "soot" on the exterior of that joint, a quick 10 sec welding and a bit of smoothing and the "fiffttt" noise was gone. No big deal but what a pain in the .....! finding it.
HTH
John Blankenship
'76 Palm Beach
Tulare, CA
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101098 is a reply to message #100995] |
Sun, 26 September 2010 23:26 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Jon,
Take a small tube and listen around the area .
Should there be a leak at the pipe, let me know so I can get them
warrantied for you
On Sat, Sep 25, 2010 at 6:20 PM, Jon Payne <embrep@sbcglobal.net> wrote:
>
>
> Thanks Dennis for the tip, I'll try that.
>
> Regarding the torque that is per the instructions from Thorley. Â Besides the LH side has no leaks and I torqued them to 45. Â Regarding the collector gasket I too think they should be reusable but knowing my luck I'll need to replace it for some reason.
>
> Thanks again Dennis!
>
> JP
>
>
> --
> Jon Payne
> 76 Palm Beach
> Westfield,IN
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,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: Thorley Header leaking at manifold [message #101124 is a reply to message #100992] |
Mon, 27 September 2010 12:20 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Senior Member |
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Guys,
Here is the update. Well I'm a little embarrassed (and happy) to say that it is not the header leaking. My last post said that I was thinking to take off the header to inspect as I was sure it was coming from the header. Before I did I took a piece of heater hose like Dennis recommended and listened for the leak but could not hear any definite leak. So then I took another close inspection all around the header flange, top and bottom, but again could find no evidence of leakage. That made me very hesitant to remove the header. I ran the engine again and listening carefully and it sure seemed as though was coming from the header. Well I really started to second guess the leaky header theory so I thought I should give a good inspection of the first few clamps after the header and sure enough I found my leak! And since the leak was blowing forward it made it sound as though the leak was coming from the header.
I tried to tighten, re-tighten and reposition the clamp but still leaked. So today I will pick up a new clamp and that should be that!!
Thanks guys once again for all who responded!
Jon
See pictures of the evil clamp below!
http://www.gmcmhphotos.com/photos/showphoto.php?photo=36101&title=clamp2&cat=5607
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: Thorley Header leaking at manifold [message #101125 is a reply to message #101124] |
Mon, 27 September 2010 12:27 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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| Jon Payne wrote on Mon, 27 September 2010 11:20 |
Guys,
Here is the update. Well I'm a little embarrassed (and happy) to say that it is not the header leaking. My last post said that I was thinking to take off the header to inspect as I was sure it was coming from the header. Before I did I took a piece of heater hose like Dennis recommended and listened for the leak but could not hear any definite leak. So then I took another close inspection all around the header flange, top and bottom, but again could find no evidence of leakage. That made me very hesitant to remove the header. I ran the engine again and listening carefully and it sure seemed as though was coming from the header. Well I really started to second guess the leaky header theory so I thought I should give a good inspection of the first few clamps after the header and sure enough I found my leak! And since the leak was blowing forward it made it sound as though the leak was coming from the header.
I tried to tighten, re-tighten and reposition the clamp but still leaked. So today I will pick up a new clamp and that should be that!!
Thanks guys once again for all who responded!
Jon
See pictures of the evil clamp below!
http://www.gmcmhphotos.com/photos/showphoto.php?photo=36101&title=clamp2&cat=5607
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Been there, done that 
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101126 is a reply to message #101124] |
Mon, 27 September 2010 12:25 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Jon,
That is good news -- and an easier repair. Thanks for the follow-up -- sometimes it seems we only hear the problem, not the solution.
Curious to know -- how much overlap is in the joint between the exhaust pipes that were leaking?
Dennis Sexton
73 PD 230
Germantown, TN
USA
-----Original Message-----
From: Jon Payne <embrep@sbcglobal.net>
To: gmclist@temp.gmcnet.org
Sent: Mon, Sep 27, 2010 12:20 pm
Subject: Re: [GMCnet] Thorley Header leaking at manifold
Guys,
Here is the update. Well I'm a little embarrassed (and happy) to say that it is
ot the header leaking. My last post said that I was thinking to take off the
eader to inspect as I was sure it was coming from the header. Before I did I
ook a piece of heater hose like Dennis recommended and listened for the leak
ut could not hear any definite leak. So then I took another close inspection
ll around the header flange, top and bottom, but again could find no evidence
f leakage. That made me very hesitant to remove the header. I ran the engine
gain and listening carefully and it sure seemed as though was coming from the
eader. Well I really started to second guess the leaky header theory so I
hought I should give a good inspection of the first few clamps after the header
nd sure enough I found my leak! And since the leak was blowing forward it made
t sound as though the leak was coming from the header.
I tried to tighten, re-tighten and reposition the clamp but still leaked. So
oday I will pick up a new clamp and that should be that!!
Thanks guys once again for all who responded!
Jon
See pictures of the evil clamp below!
http://www.gmcmhphotos.com/photos/showphoto.php?photo=36101&title=clamp2&cat=5607
-
on Payne
6 Palm Beach
estfield,IN
______________________________________________
MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: Thorley Header leaking at manifold [message #101132 is a reply to message #100992] |
Mon, 27 September 2010 13:13 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Senior Member |
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Hi Dennis,
The overlap was 50/50 and note that the pipe coming from the collector slides into the next pipe. I'm thinking that I should have more of the clamp on the pipe going to the collector (60/40 or so) but as you can see in the pictures the clamp is just before a bend in the pipe so there is no room to move it forward. Any thoughts?
Jon
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101137 is a reply to message #101132] |
Mon, 27 September 2010 13:40 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Jon
The system I bought from JimK came with flat band clamps -- 60 ft lb torque recommended (as I recall). I tightened first one bolt then the other at 25, 40 and then 60. I believe some have used a sealer as well -- but I did not. LIke you I tried to keep the point of overlap centered. Any chance the bend is so close as to affect the clamping? How much does the one pipe go into the next?
Since then I have seen the lap joint band clamp that Summit Racing sells
http://www.summitracing.com/parts/WLK-33226/
They seem like they might provde an even better seal than the flat band clamp
http://www.summitracing.com/parts/WLK-33240/
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Jon Payne <embrep@sbcglobal.net>
To: gmclist@temp.gmcnet.org
Sent: Mon, Sep 27, 2010 1:13 pm
Subject: Re: [GMCnet] Thorley Header leaking at manifold
Hi Dennis,
The overlap was 50/50 and note that the pipe coming from the collector slides
nto the next pipe. I'm thinking that I should have more of the clamp on the
ipe going to the collector (60/40 or so) but as you can see in the pictures the
lamp is just before a bend in the pipe so there is no room to move it forward.
ny thoughts?
Jon
-
on Payne
6 Palm Beach
estfield,IN
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MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101141 is a reply to message #101137] |
Mon, 27 September 2010 15:20 |
Jon payne
Messages: 495
Registered: May 2008
Karma: 1
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Senior Member |
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Dennis,
I too bought the system from Jimk and I if I recall I torqued to around 50lbs or so. I just bought a new clamp from NAPA and the instructions state to torque between 48 and 60.
I take it you have not had any problems with leaks at this location?
Jon
Jon Payne
76 Palm Beach
Westfield,IN
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| Re: [GMCnet] Thorley Header leaking at manifold [message #101142 is a reply to message #101141] |
Mon, 27 September 2010 16:10 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Jon,
My system had the two front mufflers.. and I remember the extension from the headers went over the inlet to the muffler.
I did not put much time in the system before selling the coach to Tom E..
Dennis
| Jon Payne wrote on Mon, 27 September 2010 15:20 |
Dennis,
I too bought the system from Jimk and I if I recall I torqued to around 50lbs or so. I just bought a new clamp from NAPA and the instructions state to torque between 48 and 60.
I take it you have not had any problems with leaks at this location?
Jon
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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