Logo
FULL SITE MENU

BF90 2006 Carb Model Broke Thermostat Cover Bolt

J

jlc1906

New member
While changing the thermostat the other day one of the two bolts easily broke that secure the thermostat cover.
I have read a lot of good posts on how to remove the bolt and intend to fix it or have it fixed
properly. For now I tapped the Thermostat housing with a 5/16 tap and bolted the thermostat cover
to the Thermostat Housing. The Thermostat Housing is secured to the Water Jacket Cover by the broken bolt
and one good bolt. It runs without leaks right now. Is it a really bad idea to limp along with this quick fix for now?
What is the failure mode? Water leak or water and exhaust?

When I get enough time to try and remove the bolt I thought that I would insert a bushing into the thermostat
housing and use a left hand drill. If that did not work then I was going to remove the water jacket cover and have it
removed professionally. Does that seem like a reasonable approach to removing the bolt?



Thanks again or the help.
 

Attachments

  • thermostat.jpg
    thermostat.jpg
    19.1 KB · Views: 107
Hi,
Sorry you're having trouble.
I've done these jobs for many years. The left handed twist drill technique is a good one. Many times the bolt backs out while you're drilling. But, as with almost all drilling operations, it is usually desirable to start the drill in the exact center of the bolt. Not always possible if you can't use a center punch because of space constraints or an uneven break that has the exposed remains at a steep angle that the punch or drill can't gain any purchase on.
Sometimes, drilling is almost impossible.

I recently discovered a tool called rescue bit. www.rescuebit.com that is adept at solving these issues. No center punch needed!

These things work like magic! Not only do they penetrate hardened bolts and tool steel like BUTTAH but they can also be used to cut carbide hardened metal sideways. They are not really drill bits but are special purpose coring tools.

They work best at high speed as with a pneumatic die grinder or Dremal tool.

They are not cheap, but they're a bargain compared to machine shop rates.

Check out their website. It has a demo video and the people there respond quickly to questions and filling orders. Free shipping in the States.

Note: if you buy the 1/8" bit to use with a Dremel make sure to have them break the double ended bit in half for you.

Good luck.
 
Last edited:
Hi CHawk!
I take it you watched the video? Everyone I know that's used them raves about them. Pricey but worth every penny!
 
Roger that. I can't tell you how many hours I've spent extracting broken bolts, stripped screw heads, and broken brackets. I suspect that you're in the same boat. These seem ideal for those jobs. I wonder what the heck they're made from?
 
Back
Top