Rusted exhaust manifold

Topic: Rusted exhaust manifold (Read 1699 times) previous topic - next topic

Rusted exhaust manifold

April 26, 2018, 02:18:10 pm

I'm at Bernd Ramspeck's to get a couple exhaust manifold bolts replaced. They are drilling out 3 bolts. Meanwhile they're trying to separate the three sections of the M-11 manifold which are rusted together. They've been soaking the joints with PB Blaster for 18 hours, periodically heated them with an acetylene torch and used percussive persuasion, all to little effect. Any ideas? A new manifold will cost $1800!

Re: Rusted exhaust manifold

Reply #1 – April 26, 2018, 02:39:09 pm

Cummins M11 Exhaust Manifold Casting 3080815 | eBay

Re: Rusted exhaust manifold

Reply #2 – April 26, 2018, 02:51:21 pm

If that is indeed the part you need I would do the buy it now as fast as you can.

Re: Rusted exhaust manifold

Reply #3 – April 26, 2018, 02:55:02 pm

Try soaking them in antifreeze, cleans the rust off of old tools really well.

Re: Rusted exhaust manifold

Reply #4 – April 26, 2018, 03:37:09 pm

No, not my part. It is one piece while mine is three piece.

Re: Rusted exhaust manifold

Reply #5 – April 26, 2018, 03:46:02 pm

Quote from: amos.harrison – April 26, 2018, 03:37:09 pm

No, not my part. It is one piece while mine is three piece.

Some times 3 piece can be replaced with one piece. If not already you may want to check with local Cummins parts department. One in Fort Worth, TX is good (817-624-2107)
Good luck.

Re: Rusted exhaust manifold

Reply #6 – April 26, 2018, 03:48:17 pm

This is past experience. When heating cast iron manifold to separate them, heat outside portion in one spot to make it expand. Try not to heat inner portion that slides in to outer portion. Do not use this process in conjunction with penetrating oil. Just a method. Hope it works for you.

Re: Rusted exhaust manifold

Reply #7 – April 26, 2018, 04:13:25 pm

If you can get a product called acid magic and inject a few drops in the joints it may loosen them,on the other hand you may just have to bite the bullet and get a new manifold and save some on labor.

Re: Rusted exhaust manifold

Reply #8 – April 26, 2018, 04:15:11 pm

Why are you trying to take it apart? Why not just reinstall it? Is this how bernd pads the bill, by taking stuff apart that works fine together??

I honestly don't know why you would want to take it apart.

Re: Rusted exhaust manifold

Reply #9 – April 26, 2018, 04:22:14 pm

I replaced a broken bolt back in October 2011, cleaned the surfaces and reinstalled the rusted together, three piece manifold with a new gasket. Absolutely no issues

Re: Rusted exhaust manifold

Reply #10 – April 26, 2018, 05:28:08 pm

Quote from: propman – April 26, 2018, 03:46:02 pm

Some times 3 piece can be replaced with one piece. If not already you may want to check with local Cummins parts department. One in Fort Worth, TX is good (817-624-2107)
Good luck.

You do NOT, repeat NOT want a one piece exhaust manifold on a large-displacement diesel engine-- too long a run with no "expansion joints".

Be sure they use anti-seize on the joints on reassembly.

Re: Rusted exhaust manifold

Reply #11 – April 26, 2018, 06:28:43 pm

I found a product call Kroll works much better than PB blaster. Spray it and let it sit for a while.

Re: Rusted exhaust manifold

Reply #12 – April 26, 2018, 06:43:28 pm

Totally agree on Kroil - try Napa if you want to get some local - my Napa carries it - O'Reilly's does not

Tim Fiedler

Sure Start Soft Start - home of SureStart soft starters TCER Direct - home of Generac Approved Aluminum and Copper TCER Composite cable generator-gas-prod - home of X-Riser Gas Risers for PE installation Call me at 630 240-9139
Gen-Pro

Re: Rusted exhaust manifold

Reply #13 – April 26, 2018, 07:28:29 pm

Remember a mixture of 50/50 atf and acetone beats Kroil. Just too hard to carry in the coach.

Re: Rusted exhaust manifold

Reply #14 – April 26, 2018, 07:32:01 pm

Quote from: wolfe10 – April 26, 2018, 05:28:08 pm

You do NOT, repeat NOT want a one piece exhaust manifold on a large-displacement diesel engine-- too long a run with no "expansion joints".
Be sure they use anti-seize on the joints on reassembly.

A properly designed one piece exhaust manifold utilizing high quality cast iron works on many large straight six engines OK like Detroit's 6-71 without going to a 3 piece manifold. The problem with Cummins seems to be with their OEM design. Certainly nothing wrong with a three piece replacement as it does give room for expansion and perhaps less stress with the turbo hanging off it. Look around and investigate prices and recommendations from several shops before committing. High price is no guarantee of high quality.

This seems to be a typical replacement cost:
Only $3,231.40 in labor at Cummins. They also banged me for a helicoil kit (they broke off three bolts in the head) and a new oil filter head (because they left threads there when removing the turbo oil line) for a total of $1,062.14 in parts. Plus sales tax.

And yes, making sure anti-seize is used on the fasteners is important where it might have to be done again. Not the easiest and cheapest job to replace the studs if they break.

Pierce

Re: Rusted exhaust manifold

Reply #15 – April 26, 2018, 08:26:44 pm

Kroil is a scam. Anyone who says otherwise is ill informed. Youtube search for channels: "ave" and "project farm" for proof.

Reinstall the manifold without disassembling it. Save on bernd scam labor in the process.

Re: Rusted exhaust manifold

Reply #16 – April 26, 2018, 08:49:39 pm

Don't think the manifold is removed yet,looked at the test using kroil,yes it came in last of the 5 used but it still works,it is pricey
and it does dry fast,you have to keep soaking.

Re: Rusted exhaust manifold

Reply #17 – April 27, 2018, 08:07:09 am

I'm convinced that it is the rusting of the manifold joints that causes the bolts to break. If I was planning to sell the coach or stop driving it, I might have just used the manifold as-is. But I plan to keep driving. When Ramspeck found there were no center pieces nearer than Wyoming, he authorized the techs to amp up the heating and hammering. They finally separated the pieces, destroying the end pieces in the process. The three broken bolts have been drilled out and the head re-tapped, so I should be out of here shortly after the manifold pieces arrive.

If you could have seen how hard the techs worked you would not suggest scamming.

BTW, when I noticed the manifold bolts bending on the truck "B" engine, I switched to an aftermarket multi-piece manifold. No broken bolts and no further issues. On that engine you can watch the manifold grow over time using up the available gaps in the manifold slots. On the M-11 there is little clearance at the manifold bolt holes.

Re: Rusted exhaust manifold

Reply #18 – April 27, 2018, 09:26:32 am

Manifold shrinkage is a bear on seemingly all Cummins engines. Having replaced mine, and drilled out three broken bolts while standing on my head, I wouldn't wish this job on anyone. Unfortunately the 8.3 manifold for my generation engine is only available in single piece. Comparing new and old manifolds, shrinkage was over 1/2" in length.

One thing....the proper never seize. I found some nickel/molybedium blend that is rated to 2500 degrees or so. It was hard to find. I'd sure consider slicking up the joints in the manifold with this stuff before reinstalling. Goes without saying, bolts as well.

Re: Rusted exhaust manifold

Reply #19 – April 27, 2018, 09:28:16 am

For rusty manifolds that won't separate, I buy a wall paper tray from a hardware store, put the manifold in and cover it with muriatic acid for a few hours. It won't hurt the cast iron but melts the rust away. After hosing off and drying it, I use a "liquid wrench" on the joints and then tap until it slides off.

Pierce

Re: Rusted exhaust manifold

Reply #20 – April 27, 2018, 09:58:20 am

That's what acid magic does but without the fumes,been using it for a few years .

Re: Rusted exhaust manifold

Reply #21 – April 27, 2018, 10:36:17 am

Shrinking exhaust manifold is not limited to Cummins. The heat cycles cause it and the longer the manifold the bigger the problem. Even small block Chevys shrunk. I have a Snap-On spreader tool to stretch the exhaust manifold to get the bolts out without breaking bolts. I have removed many a broken exhaust stud by first welding a washer with a smaller hole diameter than the stud, then welding a nut to the washer. The process loosens the broken stud or bolt and the nut removes it. On larger broken studs or bolts I use a small piece of pipe and weld in the center.

Re: Rusted exhaust manifold

Reply #22 – April 27, 2018, 11:57:40 am

Broken studs and bolts are tough and will try your patience. Ihave used Cranemans tricks, also they used to make a welding rod just for this it would stick to the broken bolt. Can't remember who made it though.

Re: Rusted exhaust manifold

Reply #23 – April 27, 2018, 12:02:33 pm

Quote from: bbeane – April 27, 2018, 11:57:40 am

also they used to make a welding rod just for this it would stick to the broken bolt. Can't remember who made it though.

Bruce,

Lots of water under the bridge also, but it seems like Eutectic had a rod like that.

Mike

Re: Rusted exhaust manifold

Reply #24 – April 27, 2018, 12:21:58 pm

I just use 7018 rod.

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