Another Cracked exhaust manifold

[John Jones]

I am in the process of changing my lift pump. While I was looking the other day I noticed the dreaded cracked exhaust manifold between cylinders 3/4. I plan to buy the manifold new gaskets bolts etc. I have sprayed with PB blaster twice and will do it again.

Does anyone have any advice for this project? Specifically around the exhaust manifold bolt removal? I really want to be careful, so I don't snap one off.

Thanks

[Hit_the_Rhod]

Originally Posted by John Jones

I am in the process of changing my lift pump. While I was looking the other day I noticed the dreaded cracked exhaust manifold between cylinders 3/4. I plan to buy the manifold new gaskets bolts etc. I have sprayed with PB blaster twice and will do it again.
Does anyone have any advice for this project? Specifically around the exhaust manifold bolt removal? I really want to be careful, so I don't snap one off.
Thanks

Year, make and model would help!

[mackwrench]

I've done it on my ISC.....
http://www.irv2.com/forums/f107/cumm...nt-290537.html

your ahead of the job if you've sprayed PB Blaster on the hardware, Let it soak, repeat for a few days. When trying to bust the manifold bolts loose, loosen a little, then tighten back up a little, kinda "working" the blaster into the threads if you will.....Also spray some on turbo oil feed line fitting.

Only real PITA was the turbo drain bolts, I also replaced the turbo to manifold gasket, drain pipe gasket, the drain pipe hose down near the oil filter as well.

Buy all new bolts, use anti-seize on the threads and where the bolts contact the manifold, it'll make it easier for the next guy, more so if it's you!
Good luck and post pics!

[Mr_D]

If you use oil or an anti seize compound on bolts that require a torque value be sure to find out if the torque required is for dry or lubed threads. Using a dry value on lubed threads overtorques them by 20% or so. There are charts available that show the reduction in torque vales for lubed threads.

[Smitty77]

And be prepared, to hopefully say NOT NEEDED, to remove some broken studs!

Good to get it behind you. Also, if an ISC or ISB, take a look at After Market exhaust manifolds. (I could not find one for the ISL370 we had, so another 2 piece Cummins went on.) (Oh yeah, I did it the old fashion way - wrote a check! But, we were on the road and had the work done at Rocky Mountain Cummins in Grand Junction. We came in the night before, stayed at Club Cummins, and the mechanic had it off and replaced and we were on the road to Denver close to noontime.)

Best of luck to you,
Smitty

[ladagobago]

here is a link to other posts on this replacement.
http://www.irv2.com/forums/f123/isb-...nt-308939.html

I used Blaster, wd40 and acetone /autotrans fluid for weeks and after getting bolts out found Nothing even penetrated some bolts. I ordered gaskets, bolts and turbo bolts on line. you will have to remove a lot of pipes and the turbo.
get some bolt extractors if they break off. alternative is to cut the heads off and then try to use blaster on the bolt where it enters the head. then use a pipe wrench on a bolt extractor. Need a torch to heat the turbo nuts so you can break them when hot.

[jacwjames]

I had to replace the manifold on my 8.3 Cummins a couple years ago, not too bad a job.

Didn't have any problems with the bolts, I sprayed them the day before. I changed it leaving the turbo in place, I tied it off and left it suspended, don't know it that made it easier or not but it was still very hard to get it back mated to the manifold.

If you have someone to help it would make the job easier, don't know how many times I dropped something and had to get up and go out and get it. Probably cost ~2 hours of work.

I did the job in a day.

Join the Cummins Club, saves 10% on parts.

[Twomed]

KEEP SOAKING... twice is not enough. More you soak better chance of no broken bolts.


Good Luck

[John Jones]

I should have specified what motor. (The things you forget at 5:30 am ) I have an 8.3 cummins 330 ISC. I will continue to soak and take it easy when removing. Thanks for the cummins 10% discount, I registered today.

In the event that I happen to break off a bolt, one of the mechanics at my work said I can borrow his snap-on extractor kit. Keeping my fingers crossed that I don't need it. In fact I am not going to bring it home so I don't curse myself

Thanks for all the help, I will probably start friday since I have the day off.

[Hit_the_Rhod]

Originally Posted by John Jones

I should have specified what motor. (The things you forget at 5:30 am ) I have an 8.3 cummins 330 ISC. I will continue to soak and take it easy when removing. Thanks for the cummins 10% discount, I registered today.

In the event that I happen to break off a bolt, one of the mechanics at my work said I can borrow his snap-on extractor kit. Keeping my fingers crossed that I don't need it. In fact I am not going to bring it home so I don't curse myself

Thanks for all the help, I will probably start friday since I have the day off.

Actually you NEED to bring it home, because if you are prepared, then you won't NEED it!

[tom chelbana]

On both our Cummins C and ISM engines I wrapped the turbo's and complete exhaust manifolds and exhaust pipe with heat wrap. Two advantages are it cuts down on heat in engine area and by not letting cold air get to exhaust when engine is turned off it lets the exhaust system cool down slower which keeps manifolds from cracking.

[jleamo1]

Originally Posted by tom chelbana

On both our Cummins C and ISM engines I wrapped the turbo's and complete exhaust manifolds and exhaust pipe with heat wrap. Two advantages are it cuts down on heat in engine area and by not letting cold air get to exhaust when engine is turned off it lets the exhaust system cool down slower which keeps manifolds from cracking.

Tom, how long have you accumulated on the manifold with the wrap and what product's did you use to wrap them?

[jleamo1]

John, your post "another" have you replaced the manifold before?

[John Jones]

Originally Posted by jleamo1

John, your post "another" have you replaced the manifold before?

No, I haven't done it before. I was mentioning that there was another because it happens to many people.