Broken Y-Pipe Bolt REALLY Has Me Worried

I'm getting a little desperate for ideas here... I removed my Y-Pipe a few weeks ago to clean out the VOD and replace some other things "while I was in there". One of the bolts broke off below the level of the bolt hole and I've been making multiple attempts to remove since. I started by carefully trying to drill out the center of the bolt. This was going just fine until the bit broke off inside the bolt. :banghead: I actually got that one out after quite a bit of struggle. I continued drilling with a new bit and then tried an easy out. I realize now that this was big mistake. The easy out also broke off in the bolt, of course. A really expensive "rescue bit" (~$55) that I bought almost immediately shattered when I tired to use it to drill through the easy off.

Now I've been trying to use a dremel tool with a narrow carbide grinding bit to work out the whatever is left of the broken drilling bit(s). I've made some progress with this, but not enough. I'm basically stuck at a point where I can't get an even surface on the top of the bolt to start a clean and centered drilling hole. The top of the bolt is probably around 3/8" below the bolt hole now. I assume at this point that I'm looking at Time-Sert kit to replace the threads, but I've got to somehow get that bolt material out of there.

What are my options? Should I pick up die grinder and air compressor and work with more power? Or, is my only option to completely remove the engine to take it to a machine shop? (Or someone with an EDM...) Am I beyond the point of repair? Time to look for a new engine? Wow... This was WAY more work than I wanted to get myself into.

(I don't think it will help, but I might try to post a couple detail pictures tonight after I get back home...)

I had a similar issue, broke a bolt, then broke an easy-out in the broken bolt. I ended up getting a carbide drill bit from McMaster-Carr to drill out the easy out. Normal drill bits won't work.

Helicoil or timesert will be your repair assuming the threads get goofed.

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Originally Posted by jmettee

I had a similar issue, broke a bolt, then broke an easy-out in the broken bolt. I ended up getting a carbide drill bit from McMaster-Carr to drill out the easy out. Normal drill bits won't work.

Helicoil or timesert will be your repair assuming the threads get goofed.

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Did you have any trouble getting the carbide drill bit aligned to center? That's my biggest concern right now. The exposed bolt surface in my situation is not flat... The broken bit material is causing a "bump" near the center and my drill bit just wants to slip off center. (handheld drill) In fact, I'm wondering if I need to setup some kind of drill guide to keep it aligned.

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Originally Posted by lsoasey

Did you have any trouble getting the carbide drill bit aligned to center? That's my biggest concern right now. The exposed bolt surface in my situation is not flat... The broken bit material is causing a "bump" near the center and my drill bit just wants to slip off center. (handheld drill) In fact, I'm wondering if I need to setup some kind of drill guide to keep it aligned.

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It has always been my practice, and I've found it most easiest; to use a sharp punch to punch a starting point at the center of the bolt. Then you don't have any wandering bits when drilling. Also if you can heat the aluminum around the bolt when you are using the easy out sometimes helps loosen things up.

I snapped one of those in 2005 and just drilled & tapped the block for the next size up non-metric bolt. This was after wasting 2 weeks of trying to remove it with easy-outs, torches, etc. It was way easier than locally finding an M7 bolt + thread insert, and it's been holding fine since. System was pressure tested before replacing the intake manifold just in case.

IIRC the holes in the y-pipe mounting tabs didn't have to be enlarged.

Well.... I wish I would have started with the plan of just drilling out the complete bolt with intent to re-tap the hole. I'll never try an Easy Out for this application again, but that's hindsight now. I would love to have a surface that would be friendly to a sharp punch for bit alignment, but it is not in that shape right now. I can keep trying to grind it flat I suppose, but I might need a different tool to accomplish this. The Dremel tool just doesn't appear to be producing any meaningful difference. (Will a more powerful die grinder help here? Any grinding bit suggestions?)

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Originally Posted by lsoasey

Well.... I wish I would have started with the plan of just drilling out the complete bolt with intent to re-tap the hole. I'll never try an Easy Out for this application again, but that's hindsight now. I would love to have a surface that would be friendly to a sharp punch for bit alignment, but it is not in that shape right now. I can keep trying to grind it flat I suppose, but I might need a different tool to accomplish this. The Dremel tool just doesn't appear to be producing any meaningful difference. (Will a more powerful die grinder help here? Any grinding bit suggestions?)

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So is your Y pipe removed or are you drilling the broken bold through the Y pipe hole?

You will probably find a carbide cutter in you dremal may work better than a stone. Just take your time. Only do a little work then take a break. You will get it removed, just keep at it.

Well, have you tried a steel carving bit or are you just using the carbide with the Dremel?

Unfortunately, using the small diameter easy out tools often result in this situation if the broken stud is corroded in there, instead of it just being screwed in and the head breaks off.

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Originally Posted by lsoasey

Well.... I wish I would have started with the plan of just drilling out the complete bolt with intent to re-tap the hole. I'll never try an Easy Out for this application again, but that's hindsight now. I would love to have a surface that would be friendly to a sharp punch for bit alignment, but it is not in that shape right now. I can keep trying to grind it flat I suppose, but I might need a different tool to accomplish this. The Dremel tool just doesn't appear to be producing any meaningful difference. (Will a more powerful die grinder help here? Any grinding bit suggestions?)

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Get a torch and heat it up....HOT... Then get a very small drill bit and see if you can get at least the slightest divet/hole in the center. Then begin working your way up to larger bits. The heat will soften the bit that's stuck in the bolt.

If you cannot make progress with the bit in the bolt, I'd consider again using heat and small bit all around the broken bit. Kinda drill out around it. The broken bit is likely not below the bottom of the bolt. So you may be able to remove enough of the bolt material around the bit to the point that the bit just comes out.

Again, the heat is the key. Of course be careful and try to not stray into the threaded wall. THat said, either way you go, there's going to be at least some damage. Just try to minimize it. You'll be re-threading the bolt hole anyway. Also be careful of the heated metal....where welding gloves/sleeves just to be safe.

I am not going to say this does not work, but in my experience, the hotter you get the metal you are drilling, the faster your drill bit will melt...

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Originally Posted by Kozmatic

Get a torch and heat it up....HOT... Then get a very small drill bit and see if you can get at least the slightest divet/hole in the center. Then begin working your way up to larger bits. The heat will soften the bit that's stuck in the bolt.

If you cannot make progress with the bit in the bolt, I'd consider again using heat and small bit all around the broken bit. Kinda drill out around it. The broken bit is likely not below the bottom of the bolt. So you may be able to remove enough of the bolt material around the bit to the point that the bit just comes out.

Again, the heat is the key. Of course be careful and try to not stray into the threaded wall. THat said, either way you go, there's going to be at least some damage. Just try to minimize it. You'll be re-threading the bolt hole anyway. Also be careful of the heated metal....where welding gloves/sleeves just to be safe.

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