BearKiller

Ain't it fun after you snap off an "easy out" in the broken bolt ??


In my entire life, I can't recall one instance where an "easy out" didn't just make matters worse.

I think it is partially due to the wedge-effect, in that as the extractor bites harder into the offending bolt, it is also sort of riveting said bolt into the hole by the spreading force as the taper of the extractor goes ever deeper into the broken bolt.

CaptainChrysler

The holes have been open all the way through on the heads I have worked on.

I unearthed my bolt stash and the Cummins P/N for a 12v manifold bolt is 3944593.

BearKiller

All this manifold stud talk must have caused a rush on them.

The last several nights that I have been researching them at McMaster-CARR, the size I had decided on always said "ships in the morning"; now, there is a note/flag that says out-of-stock for a few days.


Captain Chrysler --- thank you for the Cummins number; I am going to put it in my files.


Thanks.

BearKiller

Thanks to Mr Trebor's advice and heads-up, the shiny new manifold studs, nuts, and washers are at hand.


The plan is to start in the morning.


I had been having nightmares of maybe a couple of the hardest to access bolts, either snapping off, or the heads rounding away.

I have been dousing things liberally with PB-Blaster about once a week for the last few months, in anticipation of this project.


Before I came in and called it a day, I decided to see what happened when I put the 13MM socket and mile-long Pittsburgh breaker-bar onto the manifold bolts; nothing else yet removed, just seeing what kind of day to expect tomorrow.


Maybe three of the easier-to-access bolts really put a strain on the old breaker-bar; then, with one loud POP, the bolt would start turning.

I managed to get ten of them loosened a half-turn or so.

No way was that big bar going to fit onto the two bottom bolts that reside underneath the turbo; the outlet flange interferred with the swivel.

So, I dug out the old antique Indestro 3/8-drive breaker and was able to fit it in there.

A little help from a three-foot length of 3/4 pipe and those two also broke free.


So far, so good.

Trebor

For future reference which current McMaster part numbers did you end up with?

BearKiller

McMaster-CARR part-numbers :

manifold studs = M10X1.5mm 95mm-long #93210A042

These studs are plenty long, with approximately 1/2-inch protuding after installation.

The next length shorter barely came flush with the nut without a washer.

nuts = #92497A450 = box of 50

flat washers = #91455A140 = box of 100


I found it interesting that, although the original bolts are metric thread, a 13mm 6-point socket was a sloppy fit, but a 1/2" SAE 6-point fit like a glove.

wannadiesel

I find that happens a lot on bolts/nuts exposed to high heat.

NE frmhnd

I'm going to post another part number here since it was referenced in my search for parts.
Case IH 2852744
m10X1.5x65MM exhaust manifold bolt for 5200 series Maxxum tractors.

james1

Thanks for reviving this ancient thread. Between my father and I, we've owned my truck since new; it now has 120,000 miles. The boltheads on my exhaust manifold bolts are VERY badly rusted. I know the following are unusual questions:

1. Is there any virtue in my replacing the bolts now, before the rust gets so bad that a 1/2" 6-point socket will no long grab the bolthead?
2. If so, could I simply change the bolts one-at-a-time and thereby avoid removing the manifold, installing new gaskets, etc.?
3. How tightly should the new bolts be torqued?
4. Would it be okay to obtain new manifold bolts from Cummins Power South or would said bolts be subject to the same corrosion issues referenced by Trebor above?

TIA

NE frmhnd

Considering it's 20 years old and they are still holding, I'd just get a new set of bolts (or studs) and swap them in. May as well get new manifold gaskets (I think $8 at NAPA) and turbo gaskets ($9 offa evilpay) and replace them all and not worry about it.

It's really not that hard a job, I busted the old ones loose with a 3/8 ratchet. The manifold bolts go to 32 ft-lb, I can't remember the turbo bolts (no room for a socket anyway).

Just get yourself a good gasket scraper. You'll need it. And some high-temp (copper based) anti-sieze. And make sure you don't put the manifold back on upside-down the first time

NoSparkplugs

1) Replace them now and save yourself the headache down the road
2) You could yes, but it'd be better to remove the manifold, use a die grinder with 3M scotch brite roloc discs to clean the old gaskets off, install new gaskets with the bolts and then you know it'll be leak free for years to come
3) search for the oem spec on here
4) Go with the cummins or case bolts, run a bottoming tap through the bolt bores before you install them though. Also use lots of high temp copper coat upon install so that should you ever have to peel the manifold off again, its a much much easier process

Another tid bit of info, using an impact on manifold bolts seems to make them come out much easier. It sounds crazy I know, but the small repetitive blows are less likely to snap the bolt than a constant hernia inducing torque from a ratchet/breaker bar. Theres another trick I've seen to remove exhaust bolts, using an air hammer on the bolt head, turn the bolt with a wrench at the same time. I watched a video of a guy doing a cat C15 manifold this way and he got them all without breaking a single bolt. Kinda neat actually, but I've yet to try it myself.

james1

Thanks for the replies. What should I do to prep the existing (rusted) bolts for removal? Spray regularly with PowerBlaster for a couple of weeks? There is mention of utilizing some sort of wax to treat threads?

Agan, thanks much.

NE frmhnd

Spray some WD-40 or Blaster on them, stick the socket on, and turn. If they are sticky, spray them, run them back in, spray again, and back out again. Repeat if necessary. Chances are once broke loose they will back right out with your low miles and climate.
The only fiber gasket in the system is the turbo drain line. All others are stainless steel. Some will likely hit the ground before you have the manifold contorted around and out from under the hood. If you are really worried about it just shoot some brakekleen on and wipe the mating surfaces clean.
Manifold bolts torque to 32 lb-ft. I can't remember the turbo bolt torque but there's no room to get a socket and torque wrench to them anyhow. The book says to remove the heater hoses, but if you take the hold-downs off them, they will move enough to allow the work without having to drain the coolant.

Unless they are rusted to the point that you can see part of them has a smaller diameter, chances are good they won't break.

You'll need:
8mm or 10mm socket for the turbo drain line. The bolts will be a bugger to start during re-assembly.
17mm box end for the nuts on the turbo mount studs
1/2 inch socket for the old manifold bolts
13mm socket for the new
10mm for the bolts in the heater pipe hold-downs
7/16 deep socket for the clamps on the intake and exhaust pipe
shop towels/rags to plug off holes if it has to sit overnight
I'm pretty sure that's it. And a container to hold all your small pieces.

NE frmhnd

Spray some WD-40 or Blaster on them, stick the socket on, and turn. If they are sticky, spray them, run them back in, spray again, and back out again. Repeat if necessary. Chances are once broke loose they will back right out with your low miles and climate.
The only fiber gasket in the system is the turbo drain line. All others are stainless steel. Some will likely hit the ground before you have the manifold contorted around and out from under the hood. If you are really worried about it just shoot some brakekleen on and wipe the mating surfaces clean.
Manifold bolts torque to 32 lb-ft. I can't remember the turbo bolt torque but there's no room to get a socket and torque wrench to them anyhow. The book says to remove the heater hoses, but if you take the hold-downs off them, they will move enough to allow the work without having to drain the coolant.

Unless they are rusted to the point that you can see part of them has a smaller diameter, chances are good they won't break.

You'll need:
8mm or 10mm socket for the turbo drain line. The bolts will be a bugger to start during re-assembly.
17mm box end for the nuts on the turbo mount studs
1/2 inch socket for the old manifold bolts
13mm socket for the new
10mm for the bolts in the heater pipe hold-downs
7/16 deep socket for the clamps on the intake and exhaust pipe
shop towels/rags to plug off holes if it has to sit overnight
I'm pretty sure that's it. And a container to hold all your small pieces.

93flatbed

It sucks to do but, soaking them every day for a fee days then take it on a good drive to get it to temp. Shut it down and break all the bolts loose. While complaining about how hot it is. I find a few cold beers ease the hot hand problem.