I was installing a water temp sensor in the hex shaped screw on top of the T-stat housing to install a water temp guage. I had to remove the T-stat cap and plate held on by two 8 mm bolts. It came off fine but broke when I was tightening it down!
Anyone have this problem? How did you resolve it?

I was thinking I could drill it out and use over sized bolts with nuts and washers. Otherwise I will need a new T-stat housing.

 

Same thing happened to me.

You can try stud removal tools first. They failed for me. I drilled most of it out, then retapped. I got lucky and was able to use the same thread as the original and it is holding fine.

Except I wasn't drilling the hex head, I was just mounting on the side of the housing.

 

Same thing here.

I drilled out the broken bolt, used a helicoil, and then bought some new bolts from Westlake.

 

Breaking a stud or bolt when removing is unavoidable. Can be caused by being temperature welded or corroded in place.

But in 12 years of working on my FD and others cars, I have never broke one when tightening.

Why you ask? I follow Mazda's recomended torque settings and have three torques wrenches.

I suggest you all do the same to avoid needless problems.

 

Since we're on the subject, what do you do with bolts in very tight places? Does the extra assortment of torque wrenches help you access them?

Dave

 

Torque wrenches simply tighten to the manufacturers spec they do not aid in removing hard to get at bolts or nuts.

The best advise i can give you while working on this car is get your self some 3/8 drive swivel sockets (metric of course) 10mm---19mm well worth it.

As they saying goes "tight is tight and broken is too tight".

 

I have a torque wrench and I'm very familiar with their importance.

My point was since torque wrenches are heavy and awkward, how do you manage to get to all the bolts in the car? I guess that's the swivel sockets. Are these the kind that have the swivel built into the socket piece? (I guess I have all the other kinds of sockets).

Dave

 

Yes