Head bolt broke off when installing the head
#1
Head bolt broke off when installing the head
While torquing down the #12 bolt (medium length) the bolt snapped. The bolt would not torque more than 80nm. Just for kicks I decided to torque down the #13 bolt which is also the medium length and it too would not torque past 80nm. Any one have any ideas about that??
Any suggestion for extract head bolt? It broke just above the thread portion of the bolt.
Any suggestion for extract head bolt? It broke just above the thread portion of the bolt.
#3
Eazy Outs... drill a hole 'that certain size they ask for that size of bolt' & the reverse twist of the eazy out removes the now stud as it screws in.
Supposed to be easy but the drilling STRAIGHT in the center of a hardened bolt can be a PITA.
I'd try the tacking a nut to the top 1st as Jarad said though.
Small tacks but many of them, even a 120v .023 mig will work.
Supposed to be easy but the drilling STRAIGHT in the center of a hardened bolt can be a PITA.
I'd try the tacking a nut to the top 1st as Jarad said though.
Small tacks but many of them, even a 120v .023 mig will work.
#4
do either of you suggest removing the head to get access or should I try the easy out with the head still on the block?
Any thoughts as to why the bolts are torquing down fully? I chased the threads with a tap before installing new bolts.
Any thoughts as to why the bolts are torquing down fully? I chased the threads with a tap before installing new bolts.
#5
"New" bolts? Are you sure they're the same length?
As for the easy out (I think they spell it Eazy Out) anyway... sure you can try it as long as you center punch the bolt/now stud so the initial pilot hole doesn't walk. Then step up a bit to a larger bit until you get to the size Easy Out says to use for that size of bolt.
If that doesn't work then yeah, remove the head & start like Jarad said with double nutting. If that doesn't work... find a friend with a 120v mig welder that can come over & weld a nut to the stud.
Just make sure you allow it to cool, don't splash water on it etc! It'll make the weld brittle. Allow it to cool, then remove it.
As for the easy out (I think they spell it Eazy Out) anyway... sure you can try it as long as you center punch the bolt/now stud so the initial pilot hole doesn't walk. Then step up a bit to a larger bit until you get to the size Easy Out says to use for that size of bolt.
If that doesn't work then yeah, remove the head & start like Jarad said with double nutting. If that doesn't work... find a friend with a 120v mig welder that can come over & weld a nut to the stud.
Just make sure you allow it to cool, don't splash water on it etc! It'll make the weld brittle. Allow it to cool, then remove it.
#9
If you torqued each bolt in sequence to 80Nm, it's no wonder the bolt broke.
The preferred method for cylinder head bolt torque is to tighten all bolts in sequence to 30 Nm on the first pass. Then do a final pass in sequence as follows:
Long bolts: additional 75 degrees
Medium bolts: additional 65 degrees
Short bolts: additional 55 degrees
DO NOT re-use the bolts or gasket. As Rottidog mentioned, the new gasket is formed, throw it out. The purpose of the additional tightening, (degrees) is to stretch the bolt. They only stretch one time. When they are removed, they join the gaskets in the trash barrel
The preferred method for cylinder head bolt torque is to tighten all bolts in sequence to 30 Nm on the first pass. Then do a final pass in sequence as follows:
Long bolts: additional 75 degrees
Medium bolts: additional 65 degrees
Short bolts: additional 55 degrees
DO NOT re-use the bolts or gasket. As Rottidog mentioned, the new gasket is formed, throw it out. The purpose of the additional tightening, (degrees) is to stretch the bolt. They only stretch one time. When they are removed, they join the gaskets in the trash barrel
#10
I was following the torque settings from this thread:
https://blazerforum.com/forum/2nd-ge...equence-40812/
First Pass In Sequence - 26 ft-lbs
Second Pass In Sequence - 44 ft-lbs
Final Pass In Sequence - 66 ft-lbs or 89.483984587 nm
https://blazerforum.com/forum/2nd-ge...equence-40812/
First Pass In Sequence - 26 ft-lbs
Second Pass In Sequence - 44 ft-lbs
Final Pass In Sequence - 66 ft-lbs or 89.483984587 nm