Broken Intake Manifold Bolt - Need A Drill Bit

[qdeezie]

I had a collapsed lifter on my truck (see autosig) and the intake manifold bolt in the very front on the passenger's side broke off in the head when trying to remove it.

I've tried using some titanium drill bits to drill down in it to remove it, but I am able to only drill down so far. It's almost like the screw is hardened towards the tip of it. I was able to drill down in it some, but it doesn't go any further and I've broken two new bits trying to drill further down.

I admit that the bits I used were cheap titanium bits, but I have had good success with them in the past.

Obviously what I need here is a big boy drill bit. Can someone please give me some advice on what I need to look for? Is it something I can get at Lowe's or Home Depot or maybe it's another place that sells a high quality drill bit.

I do not want to have to remove the head and take it to the machine shop to get this bolt out.

 

[dakota99]

Maybe try a cobalt bit. I had a manifold bolt break in my truck one time, and i was able to drill it out with one.

Whatever you do, stay far away from easy-outs. If you snapped the bolt because it was seized, you'll snap the easy-out off inside it. I had to drill down beside the broken easy-out and then chisel it into tiny pieces with a punch towards the new hole.

 

[Donald]

What class was the bolt? 5? +1 on the lack of good luck with an Easy Out. Left handed drill bit? Heat and soak with PB Blaster?
One of the sprays that freezes? Can you grind a head and use an impact screwdriver? (The one you hit with a hammer?).

 

[qdeezie]

Originally Posted By: Donald
What class was the bolt? 5?


Not sure, it's a factory bolt.

 

[gw105]

Try a good quality cobalt drill bit, and drill all the way through to the bottom of the bolt completely to relieve pressure on the threads. The larger diameter drill bit you are able to use the better. Once done, soak it with some kroil, and use a large easy out to remove the bolt.

Don't drill too fast, and use cutting fluid or you risk "heat treating" the bolt and hardening it beyond the cutting capability of the cobalt. If that happens then you're buying carbide

Good luck!

 

[SHOZ]

Use some left handed bits. As you drill down into it then it will seize and back the threaded remains out. Use some tap oil too.

The reason people break easy outs is because they use a wrench on them instead of a tap handle. Get uneven angular pressure on it and it will snap every time.

 

[andyd]

Originally Posted By: SHOZ
Use some left handed bits. As you drill down into it then it will seize and back the threaded remains out. Use some tap oil too.

The reason people break easy outs is because they use a wrench on them instead of a tap handle. Get uneven angular pressure on it and it will snap every time.
Meh I am 1 for 3 with EZ outs. And I was using the tap holder. The first disaster over 40 yrs ago. I replaced the head. It seems to me that using something designed to work by wedging itself tightly in a hole would just expand the bolt more, wedging it tightly against the threads. I drill out sheared bolts. I get 1/8 bit going in a center punched dimple. Next a 3/16, etc. I stop a 16th under size and use a tweaking screwdriver to pry the remains off the hole's threads. Larger bolts are easier because you get more room to work with. One day I will get some LH bits, they use a better approach than EZ outs. I then will chase the hole with a spare bolt. Patience, a light touch. and lots of oil are required. I usually can get the original threads to hold proper torque

 

[mechtech2]

Can you grind the bolt first to get to a flatter and less hard surface? A Dremel type tool is great for this dental/detail work.
Maybe even Dremel a starter hole for your real bit.

 

[Trav]

I have a Snap-on set of extractors that is made to be hammered in. They do not screw in, instead they have raised spines.
They will round the hole before they break, just hammering them in most of the time loosens the broken bolt if its seized.

Left hand cobalt drills work amazing on broken bolts, the heat generated from drilling many times loosens the bolt to the point it will spin out while drilling.

http://buy1.snapon.com/catalog/item.asp?item_ID=158&group_ID=1254

 

[mva]

Originally Posted By: gw105
Try a good quality cobalt drill bit


+1 on the cobalt

Start small and drill a second time with a larger bit. Then an easy out, if need be.

Left hand bit sounds like a good idea too.