broken exhaust manifold bolts
Senior User
Joined: Jun 2001
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broken exhaust manifold bolts
I'm sure some if not most of you guys have had this happen to you before and I would like to know what you did. I have six bolts that are broken off in the block . There were seven but I drilled one of them out and tapped it. That was when the engine was sitting on the garage floor. Then I got impatient and just went ahead and put the engine in. I knew I would regret it later and now I am. Also, every drill bit I tried would wear out after drilling about a 1/4 inch in. Its awkward enough to get the drill in there now let alone get any pressure behind it. What types of drill bits do you guys use that will work good. I don't mind buying an expensive bit if it will do the job. I know some of you have leaned from experience on this. Thanks for any help.
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broken exhaust manifold bolts
This may not be the answer that you are looking for but I would pull the head(s) and take it/them to a machine shop to have the bolts extracted. Drilling and tapping one or two is one thing, but six? Good luck.
Mike/Ohio
Mike/Ohio
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From: Gainesville, FL
broken exhaust manifold bolts
Nick,
You've got to pull the head. If you had an elbow drill, maybe you could do it but, how can you insure a straight drill from those angles created by hanging over the fender and dealing with the inner wheel well.
Personally, I'd pull the engine back out and drill them myself. You'll save yourself the expense of a head gasket set and dealing with the intake gaskets and valve adjustment.
All drills suck when it comes to this job. You may want to buy a drill sharpener. And for God's sake don't break off an extractor in the head! In fact, don't even try to use an extractor.
Good Luck, Have Fun,
KingFisher
You've got to pull the head. If you had an elbow drill, maybe you could do it but, how can you insure a straight drill from those angles created by hanging over the fender and dealing with the inner wheel well.
Personally, I'd pull the engine back out and drill them myself. You'll save yourself the expense of a head gasket set and dealing with the intake gaskets and valve adjustment.
All drills suck when it comes to this job. You may want to buy a drill sharpener. And for God's sake don't break off an extractor in the head! In fact, don't even try to use an extractor.
Good Luck, Have Fun,
KingFisher
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From: Inthepast
broken exhaust manifold bolts
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I agree. You should let a shop do this task for you. You won't regret that.
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I agree. You should let a shop do this task for you. You won't regret that.
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broken exhaust manifold bolts
I couldn't agree more.
That is ONE BIG piece of sandwich that's been biten off
and the right place for it go is amachine shop.
Dennis
Please Don't Ask Me Any Tough Questions As:
"I'm Saving Up MY Memory For When I Develop Alzheimer's"
78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
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That is ONE BIG piece of sandwich that's been biten off
and the right place for it go is amachine shop.
Dennis
Please Don't Ask Me Any Tough Questions As:
"I'm Saving Up MY Memory For When I Develop Alzheimer's"
78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles
Senior User
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broken exhaust manifold bolts
Well I was hoping for some better news, but you guys are probably right. I would really like to do this without pulling the head though. (The six bolts are all on the same side). What if I just drilled down about a 1/4 inch on each one? That way there would be enough thread to hold the bolt in and reduce the risk of drilling at a bad angle. Otherwise, do you think a shop would be willing to drill them out with the engine still in the truck, or would they laugh in my face. I guess I'm just trying to think of all the options.
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From: fortworth usa
broken exhaust manifold bolts
Is this a FE motor? Must be , man if its all on one side pull the head. A machine shop most likely wont do it on the truck.
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From: Inthepast
broken exhaust manifold bolts
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I doubt you will find anyone willing to do it in the truck. I know it's a pain pulling something, but the head is easier to pull than the whole engine anyway. I don't mean this to sound harsh, but bite the bullet and start wrenching. You'll spend more time anguishing over doing it than actually doing the work. :-) Been there done that.
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I doubt you will find anyone willing to do it in the truck. I know it's a pain pulling something, but the head is easier to pull than the whole engine anyway. I don't mean this to sound harsh, but bite the bullet and start wrenching. You'll spend more time anguishing over doing it than actually doing the work. :-) Been there done that.
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broken exhaust manifold bolts
Since you have some many to do, and you appear determined, expect to spend some money on some good bits and taps. Don't get fooled by the titanium COATED ones either. I assume these are all broken off inside the head. If they are not, try lots of penetrating fluid, time, and a small pipe wrench to grip the protruding end of the broken bolt. I have had best luck drilling these suckers by : 1) using tap oil to keep the bit cool 2) drill the bolt in small pulsations on/off on/off rather than running the drill at full RPM. 3) give the drill a good push when you do number 2 4) start with smaller drill bit sizes to start a pilot hole. 5) Buy some good taps too, expect to eat a few of them up.
If you know the bolt size, post it today and I can post the drill size for the tap.
Good Luck.
If you know the bolt size, post it today and I can post the drill size for the tap.
Good Luck.
New User
Joined: Jan 2002
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broken exhaust manifold bolts
Try using Cobalt tipped drills... Don't know where you get them from in the USA but in England we HAD to use them for drilling out rivits on the fan housing of a VAX8650 (A computer circa 1982 ish)
Cobalt tipped drills are VERY expensive bit they will drill through a hardened steel drill stuck in a hole.
Cobalt tipped drills are VERY expensive bit they will drill through a hardened steel drill stuck in a hole.
Senior User
Joined: Nov 2001
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From: Virginia
broken exhaust manifold bolts
I had the same problem with a '74 360 although I didn't even get the chance to break bolts. The bolts had never been removed, but I had to get the manifold off due to a stuck exhaust riser valve. The heads of the bolts were so rusted that they didn't fit into any socket in my wrench set. I tried everything until the wrench slipped and I cut open my wrist on the power steering filler tube 
. I got 8 stiches and decided to let the professionals handle it. I'm glad I did.
Mark
. I got 8 stiches and decided to let the professionals handle it. I'm glad I did.Mark
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broken exhaust manifold bolts
If you dont want a machine shop to do it.. do it yourself but as others have said and I will reiterate.. only one way to drill through a bit of hardend even titanium... cobalt bits. Not cheap, but you can get them at most large hardware store chains. One of the right size should run about 15-25 bucks but once you buy it you should never have to replace it.. unless you try drilling through modern tank armor. Pull off the head to get angle. Some said it would be a lot of work but you will be very surprised at the speed that the cobalt bit will eat through the broken bits and bolts. Everyone should save up and have a set on hand just because they make any metal drilling amazingly fast. ANd no need to worry about sharpening.. If you manage to dull a cobalt bit.. good lord dont know what yer doin to it.
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Joined: Jan 2002
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From: "tween the cotton and tob
broken exhaust manifold bolts
Well heres how I do it in the truck. I have a 90 degree drill. Its made more for aviation work, but will work anywhere. The bits are solid carbide and screw into the drill chuck. The most important thing is to grind the broken bolt flat if any extends. A very accurate center punch is needed. Start with a small bit.. less than 1/8 and work yur way up. Drill absolutely dead on or all will be in vain. Yes it can be done... and with the right tools. But just like everyone else suggested, with that many to do... gaskets are cheap! pull the heads. I dont think they charge all that much, all things considered.
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From: corapeake usa
broken exhaust manifold bolts
i don't know if you've solved your problem or not yet.if your heads are cast you can take a nut that is a little bigger than your bolt hole and mig weld it to your broke bolt. apply some heat(don't go crazy) you then should be able to take it out with a wrench or socket. this has always worked for me. hope you have the same kind of luck.