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Topic: Exhaust Manifold Failures and Consequences (Read 4790 times) previous topic - next topic

Re: Exhaust Manifold Failures and Consequences

Reply #25 –
Quote from: Barry & Cindy –
Robert, What was your technique to not break any exhaust manifold bolts.

We heard that the ISC has a two piece exhaust manifold, but it is not specified for the C8.3. We had ours changed because of shrinkage and several bolts were broken.

I first hit all of the bolts with PB Blaster for a day or two before I was going to start but in the end, I'm not sure how much it helped because when I first started removal, the first few didn't come off and seemed like they might break if more force were exerted.  I went to auto zone and picked up CRC Freeze Off which immediately freed every last bolt up when accompanied with a 2' breaker bar and a light hammering technique.  Reassembly is easy. 

I did the job slowly, working a couple of hours a day for 3 days.  It is not the most comfortable position to be working in and your back and hamstrings will be in trouble for a few days. 

Quote from: Michael & Jackie –
Regarding costs for an ISM, we paid Tyler Truck Center, ism certified, $1249 for the job.

That is a really great price. 
Robert
Build # 5304
1998 34' U270 Cummins 6CTA8.3

Re: Exhaust Manifold Failures and Consequences

Reply #26 –
If the exhaust leak is big enough and lasts long enough as mine did the exhaust gases scorch the cylinder head. My exhaust manifold had shrunk almost an inch, was not secured properly, see my previous post, and the head had to be removed and resurfaced by a machinist. I was fortunate that I did not have to purchase a new head at the quoted price of $4000. Glad I had the Cummins dealer in Scarborough Maine do the job. Also happy I was a Cummuns Power Club member and got  10% discount on parts and labor.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Exhaust Manifold Failures and Consequences

Reply #27 –
I have a 5.9L ISB which is basically same as an 8.3L Cummins.  I've not missed many of the things that can and will go wrong after 400,000 miles of Hot Shot'n from here to there.
Manifold cracking can be traced to not allowing for (proper) warmup before hitting the road (been there, done that & never again). 
When replacing the manifold (forget repair), replace all of the fasteners (bolts) too, sequence and make sure they are torqued to spec and re-torqued after a few cycles.  Allow time to warmup (especially in colder weather) and time to cool-off (ALL THE TIME). 
Give consideration to seasoning the manifold. Simply warm up and shut down a few times before hitting the road.  pc
S/W Houston 95" U320C SE/40' 
Build #4778  Cummins M11
Repairs & Covered RV Parking (BAO)
PPL is close..

Re: Exhaust Manifold Failures and Consequences

Reply #28 –
Be glad it was not the cylinder head.  I had to replace that due to a broken bolt hole.
1994 U225
build #4514