Broken exhaust manifold bolt in the head

[Forrest Nearing]

I somewhat agree...



but really, this bolt hole isn't going to make or break a trip to the moon... drill it out, try to chase it w/ a tap... if that doesn't work, drill it out for a heli-coil... if you're slightly off center, wallow out the bolt hole on themanifold and run it!



but I did consider saying just run it w/o that bolt

 

[JLEONARD]

Bill, Is that a stainless cap screw? Looks it in the picture. If it is I'll comment.



I would not vote for using it as is... fix it. It's a new head, get it right.

Looks like there is room in there ot work.



Jay

 

[1stgen4evr]

I will jump in here with my two cents and I realize that there are some pretty knowledgable fellows that have already told you how it can be done.



From the pictures, you ain't gona get it out with welding. (My opinion) If you want to try, use a mig and HB18 or better wire. Use a washer held in place with something fixing it exactly in place (something besides your fingers or pliers) from the upper hole in the manifold. It would be useful to first drill a hole about one sixteenth dia through the broken remains. This will weaken the grip on the threads, which must be pretty firm considering that you wrung off the bolt and then the remnant and didn't get it to move. Be very careful drilling as you break through the end of the remnant. That is where it will try to break off.



You can fix a drill guide over the hole same as holding the washer in place. When you get the washer welded on, weld a length of 1/4 by one (on edge) on that and grip it with the vise grips and wiggle it to (hopefully) break the grip in the thread. Heat on the metal around the hole is usefull sometimes. If your weld grip fails, you will be deep enough that you might as well get the dremel (or similar tool from Sears) and with small stone points, open the hole to the minor diameter of the threads. You will need very good lighting. When you have it to that point, you can pull the threads out with a prick point and needle nose pliers.



Be sure to cover that open rocker box and stuff some wet towel down the port.



I truly believe you can skip the welding part and go to the drill and dremel tool. That cap screw is one tough mother and ain't gon'a give up without a fight.



As for extractors, I make mine from a lathe tool of the proper size for the pilot hole. I grind it so that the side has a edge grip in the direction of removal. It looks very similar to the common side fluted extractor but the material is MUCH better and with the regular tool, there is no 'bite'. The lathe tool is the toughest material I know of. The extractors that have the 'twist in' sprial have never worked for me. They only swell the remnant and make it that much tighter.



I am guessing but I suspect you got a standard thread cap screw mixed in with the mm bolts.



In the end, there is always the heli-coil.



James

 

[bgilbert]

I appreciate everyone's input on this. I am very primitive when it comes to drills/drill bits, taps, etc. I have just about every nice hand tool imaginable to work on the Cummins. Done just about every bolt on/bolt off job to the engine, but for some reason I am very intimidated (scared) with this. I'd love to just slap the manifold back on and be done with it. But with future plans of a neighborhood of 100psi of boost, I better do it right.



Here's what I've done so far. Started a hole, I'm up to a 5/32" drill bit/hole. Unfortunately, I'm off center, slightly to the bottom of dead center. The next step up in drill bits I own is DULL. Yeah yeah, take my butt down to the parts house. When I jump up to a bigger bit, it starts cutting into the head. Since the hole is off center So I tried a 5/32" extractor, well I guess you need a small tap wrench to turn it, cause my primitive drill just spins on the extractor that is 'stuck' in the head. I'm sure this is elementary stuff to many of ya, but I never done anything like this. I really don't want to screw up this new head. I think I'm gonna pull it again, take it to a shop and let them deal with it, cause I don't have the tooling to do it right, without screwing up something.



Guess I'll just stick to governor spring installs, injection pump R&R, clutch, heater core jobs etc, and leave the 3rd grade stuff to the pro's.



Last question. I've already torqued the head down. Do I need a new headgasket when I R&R the head again?

 

[MMiller]

No need to pull the head again. There is no reason why it can't be taken off in chassis. You 'should' have a new gasket if you pull the head..... but thats a story for a differnt day. I'd hate to take the risk.



I've never seen an extractor that goes in a drill, do NOT do this again. Use a tap handle, a small wrench, or a small crescent wrench. Put the extractor in the hole, and tap it in with a hammer. Then try and screw the bolt out.



If it won't back out with the extrcator, please give up before you break the extractor off, then the next step will be stepping up drill bits until you get close to the threads. Then as James suggests, grind the bolt slowly with a dremel or die grinder.



Remember, this takes patience. Do you have any friends in your town that are mechanics? Anybody that will come over one evening and help you? I'd come over and help you out, but its a little far to come over after work and help you out.



Don't be scared. I'd be more intimidated with a gov spring install, thats playing with the part of the pump that keeps the engine together. All your doing on this project is getting a stubborn bolt out of a hole. Should be a cake walk!



Michael

 

[RBergman]

rigid tools has a extractor set that come with drill guides

with this you can not go wrong i have used it on many cummins m-11s'



http://www.ridgid.com/Tools/10-Screw-Extractor-Set/index.htm



the other thing to do is check for a mobile machenest to come to you and do it in place



but i bet you could do it



also did you try left hand drill bits?

 

[Gary - K7GLD]

We used to break off bolts of that approximate size on the newspaper press - usually in a blind hole on a sliding gear to engage/disengage a printing unit.



After several pretty trying incidents, I finally bought reverse twist drill bits as suggested earlier - they NEVER failed to quickly remove the busted off bolt - just use reasonable care to align the starter hole with a good quality smaller size bit, then hit it with the reverse twist one. Usually the heat generated by drilling loosens the remnant piece, and it backs right out on the drill bit.



We also made up a proper sized bolt that we drilled a carefully centered pilot hole in to thread in when the broken piece was far enough down in the threads to allow it's use - made drilling a pilot hole into the broken piece on-center a snap.