Exhaust Leak with BD Exhaust Brake Active

[JHumphries]

I have been noticing a squeal when I have the exhaust brake on. I thought it was an air leak, but when I called BD, they told me it was most likely an exhaust leak.
So, I removed the exhaust brake and saw no signs of a leak. No soot any where outside of the brake.
I re-installed the brake and started the truck and found the leak.
The leak is coming from the exhaust manifold, either cylinder #1 or 2.
I took the manifold out. As it turns out #1 and #6 were both leaking.
I got new gaskets and re-installed the manifold.
Now the leak is worse. I torqued all of the manifold bolts to 32 ft-lbs in the sequence the dealer gave me.

So, anyone have any experience with these things?

 

[ScottLewis]

I've heard that manifolds can warp and cause leaks. You might try thicker than stock gaskets like those race cars sometimes use. Best approach would be to have manifold planed if you can bear the cost.



I'm attaching a copy of the manual section that spells out the steps for torquing the manifold. A old standard in torquing a manifold is to do it in sequence as shown but also do it in stages. First, torque all to say 20#, then go back over, in sequence, to 25#, then up to 32#. Then I'd go back over them all at 32#.

 

[NIsaacs]

I had this problem for years on my Cummins powered Ford, changed gaskets several times and finally I got mad and really screwed the bolts down, then broke 2 ears off the head Turned out the head was never machined flat, the manifold was fine. This was about 13/14 years ago. After the machine shop welded new ears on and surfaced the head, no more leaks.

Nick

 

[JHumphries]

I got those instructions while I was at the dealer. I followed them exactly including the torque the four center ones again.
As for the torqueing in stages, if the final torque was higher I would have, or if it was like the old slant six with the tabs holding both manifolds,
For this, I didn't see the point. Tomorrow, I will take all of the interference out and torque the manifold a little higher.
I may leave the intake tube off of the turbo so I can check the torque when things heat up.

 

[jelag]

Over the years I've had several of these trucks that I've worked hard pulling large heavy trailers. . I do nothing to improve the performance of the engine in the form of tuners, or injectors as I needed the truck to last 500K miles... .

I had no problem with the 01 but the 04. 5 and the 05, my BIL's 03 and my son's 05 all have had to replace the exhaust manifold to prevent leaks...

In each case they were warped often to the point where they might break one or two of the bolts or won't bolt back up when removed. . In each case we purchased the ATS manifold and installed them with the HD gaskets and new bolts... I know on the 03 he now has at least 50K miles since the installation, the 05 that I drive must have 40K since the install... . for us, that's been the fix...

Also as a foot note. . if you've had the exhaust brake off... you need to re-check the clamp between the turbo and the exhaust brake after 100 miles or so... than its good until its removed... . the heat cycle after installation will allow it to loosen a little...

Hope this helps...

 

[JHumphries]

I torqued all of the manifold bolts to 40 ft-lbs two times in sequence.
The leak is still there. It's a big leak too. It sounds like an open ended air line, just blowing, no whistle. Before it was a small leak, it squealed.

 

[jelag]

Call ATS and order up a manifold, everyone I installed worked perfectly... they are at least 50% heavier than the stock units with castings between the runners to prevent warpage...

 

[cerberusiam]

Remove the manifold an get a straight edge on the head to make usre it is not warped then replace the manifold. Either it is badly tweaked or cracked, or the head has issues.

 

[JHumphries]

I ordered a BD manifold and set of studs from Geno's.
When I take this manifold off again, I will check it with a straight edge.
At least I don't have to drill for a pyrometer now!