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Snapped water pump bolt in block?

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Old Aug 6, 2013 | 12:47 AM
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Default Snapped water pump bolt in block?

So, i snapped only one waterpump bolt during the teardown of the block, but it has proven to be the most stubborn bolt removal i have ever had before. After countless drill bits/drilling, failed welding attempts, going to the store to buy cobalt drill bits, then making a deep enough hole to force an oversize 3/8 drive torx bit into the center of the bolt, and finally snapping the torx bit off in the hole trying to extract it, so now there is no hole and the bolt is now impossible to drill because now there is a very hard steel torx bit in it. Let me explain that there is no stub to grab, it snapped off clean with the face of the waterpump mounting surface.

So now i've concluded that there are only two real options here, go without that bolt holding the waterpump on and hope that it seals, or mounting the block and a large drill in some kind of jig that will hold both items from moving, and slowly drilling the bolt out for a helicoil. Or taking the entire block to a machine shop to have them remove or drill out the bolt.

Anyone ever go without a bolt on a waterpump and not have it leak or cause problems?
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Old Aug 6, 2013 | 12:49 AM
  #2  
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There are 13 bolts holding that on, I doubt one is going to make any difference at all.
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Old Aug 6, 2013 | 06:47 AM
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Yeah, what Sean said, or you can do what I did after I snapped a tungsten carbide tap in one of the holes. Use diamond tipped Dremel bits to cut out the torx bit.

Dremel 7150.
http://www.toolup.com/dremel_7150_di...FSzhQgodiVMA8A

Used in short bursts (10-15 seconds of moderate pressure, then let cool for 10-15 seconds), these small bits made quick work of the tap as I cut across it in a few minutes and the pieces fell out. I only needed two of these bits - the first lost its tip from overheating.

After you get the remnant out, then using the old water pump as a drill guide, go at the bolt again with those cobalt bits. The original bolts are not that hard. If, as likely, the original threads are destroyed, the best solution is Time-Serts. Heli-Coil, which is more readily available (sold at Autozone) would be plenty strong enough for these very low torque bolts, but may not provide the seal needed, as you said this hole penetrates the water jacket (I didn't know any of the WP bolt holes did that). The 6mm Time Sert kits are expensive.
http://www.amazon.com/TIME-SERT-Metric-Thread-Repair-1610/dp/B001JK802K http://www.amazon.com/TIME-SERT-Metric-Thread-Repair-1610/dp/B001JK802K


Or what Sean said.
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