Thermostat bolt snapped - advice appreciated

[C4BKG]

Hi all, need some advice, replaced thermostat with a new one, and then had small leak, I think this was due to using blue loctite on threads and bunged up the holes to properly seat housing, So I removed housing again, and was using a bolt to just clean out threads and sure enough a bolt head snapped off, just what I was trying to avoid. its the lower left, with about 3mm sticking out but can't get a vice grip around it.- area is too tight. I'm thing getting someone to weld a bolt to it and then unthread> think that is less evasive than drilling into aluminium bolt and there is still some bolt sticking out. Any advice? anyone know a mobile welding service to come out to farnham Surrey to do quick weld? Here is pic of bolt.
I will use a tap to clean out other 3 threads and replace all bolts with you ones, guess this bolt was stressed from age and me cranking it too much

thanks

 

[corneg1]

You have my sympathy - thats not a great place for access.

If you can find someone who can weld a nut on I guess that should work. In theory, it shouldn't be in too tight. I think they just need 10Nm - which is nothing really.. Not sure if you can find a bolt extractor tool that would grip something that small.

In my experience, if you get a leak after replacing this or the water pump, its not because the bolts are too loose (assuming you torqued up to spec). Its more likely to be debris on the sealing face from the previous gasket.

Good luck - hope you can get it out smoothly.

 

[Griff66]

U could try using a easy out , basically drill in centre of bolt tap in easy out as u turn screw extractor It bites into snapped bolt if done correctly they are pretty good .they come in all sizes a 1/8 or 5/16 one might do it .

 

[fireman]

at least your lucky it did not break flush. get hold of MAF torch , heat, cool, heat cool, some oil, keep repeating process . get lock grips on stud and move back and forward slight movement, patience is the trick, i have had so many runs with this problem, hours, heating cooling, steel into alum, []

 

[garrycole]

You might want to try Irwin bolt-grip (https://www.amazon.co.uk/Irwin-Bolt-Grip-Remover-Expansion/dp/B000QW6K8I/ref=asc_df_B000QW6K8I/?tag=googshopuk-21&linkCode=df0&hvadid=208050023643&hvpos=&hvnetw=g&hvrand=18181879386918100346&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007225&hvtargid=pla-384112949473&psc=1), saved my bacon a few times. The trick is the jerk them onto the remaining bolt/stem so they bite, then they grip harder the more you turn. Depends on the amount of the bolt left protruding from the casing. I had a nightmare with the exhaust manifold bolts and ended up drilling out and re-tapping, not easy with a hard bolt and soft casing.

Hope this helps?