Thermostat housing broken bolt

[brickwhite]

What's the best method to remove a broken bolt from the thermostat housing.

-I'll try some heat, penetrating oil and vise grips first.. the move on the the welder....

Is the bypass is cast iron?



the thermostat was pretty old and not closing/opening all the way.

[Loren At 65GS]

Yes, it is cast iron. I would use my oxy acetylene wrench to cherry the bolt a couple of times allowing to cool between. Looks like there is enough to get a vise grip to grab onto. If not, weld a nut onto it and use a wrench. Copious amounts of penetrating oil is good too.

  Best of luck,
  Loren
 

[brickwhite]

I had enough old bolt to weld a nut to the top, I broke the weld 2 times before it came loose.

Made sure I tapped both holes again before reassembly.

Thanks for the advice. I always hate drilling and tapping old bolts.

[Loren At 65GS]

 Excellent !  Happy to see it came out. I concur drilling broken bolts out, is not a fun task.
 We use to drill out so many exhaust manifold bolts when I was an Audi tech, I had a guide fixture that helped keep the bit centered and straight. Oh well, that seems like another life time. lol

  Loren

[GS66]

Had the same thing on a 401 water pump bolt.