Broken valve cover bolt

[Landman2000]

Hey guys,

Replacing valve cover gaskets today and the very back drivers side bolt (hardest one to get to) broke. I noticed it was tight and sprayed it with PB Blaster. I thought it was turning but the head snapped off. I tried getting it with some vise grips clamped on tight but there is not much room to work. I would really like to avoid breaking it off flush.

Any input on the best way to get this out?

 

[Landman2000]

Just went and picked up a couple nuts. Going to try and weld one on and turn the bolt out. Fingers crossed.

 

[nissanh]

Heat the remaining piece of bolt that is stuck into the cylinder head.

 

[Landman2000]

Went ahead and purchased some of these. Did some research and they look to be pretty high-quality. Won’t have them until Wednesday though.

Hope they do the trick.

 

[badlander]

I had the same one break on mine. I was able to drill it out using right angle attachments, etc, but it was next to impossible because of lack of work room. A few months ago I replaced my master cylinder booster unit and when I had it out I was amazed at how much easier it would have been to drill out that broken bolt without the MC in the way, a straight shot in with a drill! You can get the master cylinder unit out in about a half an hour and if it ever happened to me again I would deffinetely go that route.
Good luck!

 

[rexington14]

Good luck man. I think one forum member actually ended up pulling the engine when this happened.

 

[TRDdrew]

induction heater and some vice grips. good luck

 

[2001LC]

Welding nut on stud, is the best way to go.

 

[TahoeZ]

Heating it, either with a torch or induction, is going to help a ton. If you can't get it to break loose, one option is to drill it out completely and replace with a through-bolt and nut. As mentioned above, if you remove the brake master there's a lot more room to work.

 

[excessive]

the only true way to access / drill out that bolt is to pull the engine.

 

[Landman2000]

I had the same one break on mine. I was able to drill it out using right angle attachments, etc, but it was next to impossible because of lack of work room. A few months ago I replaced my master cylinder booster unit and when I had it out I was amazed at how much easier it would have been to drill out that broken bolt without the MC in the way, a straight shot in with a drill! You can get the master cylinder unit out in about a half an hour and if it ever happened to me again I would deffinetely go that route.
Good luck!

Good to hear. I have some extractors coming tomorrow. They are my last resort before drilling. I’ve tried welding nuts on but they just kept twisting off along with a little of the bolt each time. I preheated the heck out of the area too..This puppy is seized. I do have a Milwaukee M12 right angle drill. If it comes to that I’ll drill the bolt out and retap with a 6mm tap. If that doesn't work I’ll through bolt it. I’ve heard you need a scanner to properly bleed the brake system if you remove the master cylinder. If thats not true. I’d definitely consider going that route.

 

[Landman2000]

Welding nut on stud, is the best way to go.

I tried several times. Each time the nut would twist off with a little more of the stud. Good weld and I heated the area real good too. I’m down to about a 1/2” stud now. This thing is seized. If the extractors I have coming tomorrow, don’t work. It looks like I’ll be drilling.

 

[bpalmer7440]

Good to hear. I have some extractors coming tomorrow. They are my last resort before drilling. I’ve tried welding nuts on but they just kept twisting off along with a little of the bolt each time. I preheated the heck out of the area too..This puppy is seized. I do have a Milwaukee M12 right angle drill. If it comes to that I’ll drill the bolt out and retap with a 6mm tap. If that doesn't work I’ll through bolt it. I’ve heard you need a scanner to properly bleed the brake system if you remove the master cylinder. If thats not true. I’d definitely consider going that route.

I had this happen on exhaust flange bolts (break off every time I welded on a nut and applied torque). This happened on both of the bolts *until* the bolts broke off slightly below the surface. The next bolt (actually a thick flat washer followed by a bolt), the broken bolts came out in one piece. These bolts were so hard from the heat cycles that I could not drill into them. It seemed like there was something about getting past the surface that allowed them to finally come out. After this I just ran a tap through them and installed new studs.

 

[scubadoober]

A good low profile metric stud puller is another option. Not the universal ones, but the size specific.

 

[Landman2000]

A good low profile metric stud puller is another option. Not the universal ones, but the size specific.

I have some of those coming tomorrow not real low profile, but they are high-quality and size specific.

I really don’t think it’s going to do anything but break off flush so I’ve come up with another option I think will work.

I have about a 3/8-1/2” of stud remaining that I was able to clean up with a 6 mm Die. I found these T nuts at Ace Hardware and threaded one over an old valve cover bolt along with a flange nut and welded them together. I gave it a trial run without a valve cover gasket and it seemed like it will work. The T nut fits perfectly into the valve cover hole and catches the remaining stud.

My only concern is the strength of the T nut threads.. The nut welded on top is just for the socket. My gut tells me it will be fine. If not, I just gotta pull it back off and start over.

What do you guys think?

 

[toyotandrew]

I have some of those coming tomorrow not real low profile, but they are high-quality and size specific.

I really don’t think it’s going to do anything but break off flush so I’ve come up with another option I think will work.

I have about a 3/8-1/2” of stud remaining that I was able to clean up with a 6 mm Die. I found these T nuts at Ace Hardware and threaded one over an old valve cover bolt along with a flange nut and welded them together. I gave it a trial run without a valve cover gasket and it seemed like it will work. The T nut fits perfectly into the valve cover hole and catches the remaining stud.

My only concern is the strength of the T nut threads.. The nut welded on top is just for the socket. My gut tells me it will be fine. If not, I just gotta pull it back off and start over.

What do you guys think?

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How'd the t nuts work out for your valve covers? I've got the same problem, but on the passenger side.

I've been reading a lot of threads and seeing mixed reviews. Several posts are saying that welding nuts has only taken more of the bolt off, I've seen a post that said a right angle drill worked to drill it out, another post that suggested using G clamps and some RTV. I've been soaking the broken stud with PB blaster and ATF for days, heating with a torch, trying to back it out with vice grips, double nuts, etc. with no luck.

One of the ideas I'm thinking about trying is taking another one of the bolts, cutting the bolt head off and welding the extra threads it onto the stuck stud to lengthen it and simply tighten it down with a nut. If it doesn't work, I can cut it off and still have the option of attempting to drilling it out, or use some G clamps.

One thing is for sure, I'm not going to pull the motor. Fortunately we can learn from the experience of one of the other members here: my living nightmare. valve cover gasket replacement turns into engine out job - https://forum.ih8mud.com/threads/my-living-nightmare-valve-cover-gasket-replacement-turns-into-engine-out-job.1308907/

 

[Landman2000]

How'd the t nuts work out for your valve covers? I've got the same problem, but on the passenger side.

I've been reading a lot of threads and seeing mixed reviews. Several posts are saying that welding nuts has only taken more of the bolt off, I've seen a post that said a right angle drill worked to drill it out, another post that suggested using G clamps and some RTV. I've been soaking the broken stud with PB blaster and ATF for days, heating with a torch, trying to back it out with vice grips, double nuts, etc. with no luck.

One of the ideas I'm thinking about trying is taking another one of the bolts, cutting the bolt head off and welding the extra threads it onto the stuck stud to lengthen it and simply tighten it down with a nut. If it doesn't work, I can cut it off and still have the option of attempting to drilling it out, or use some G clamps.

One thing is for sure, I'm not going to pull the motor. Fortunately we can learn from the experience of one of the other members here: my living nightmare. valve cover gasket replacement turns into engine out job - https://forum.ih8mud.com/threads/my-living-nightmare-valve-cover-gasket-replacement-turns-into-engine-out-job.1308907/

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The T nut with a nut welded to the top is working great for me. I didnt torque it to spec but its tight and I marked it with a paint pen and it hasnt moved. I actually bought some other T nuts that are beefier with deeper threads but haven't had to use them. Here is a link to them. I’d go with these.

uxcell M6 T-Nuts, 12pcs Carbon... https://www.amazon.com/dp/B0CSK4WHLZ?tag=ihco-20

Also, I made sure to put extra FIPG in the corner where the bolt broke. My guess is that would probably be enough since the valve cover is heavy cast aluminum. I honestly think you could probably do without that bolt completely and have no problems.

 

[Landman2000]

Also, with the amount of the bolt you have remaining, you will be good to go. I had less than that (because I tried welding nuts to it several times) and it worked good for me and that’s with the shorter T nuts. Get the ones in the link I sent you and you’ll be good.

 

[toyotandrew]

Also, with the amount of the bolt you have remaining, you will be good to go. I had less than that (because I tried welding nuts to it several times) and it worked good for me and that’s with the shorter T nuts. Get the ones in the link I sent you and you’ll be good.

Amazing, so glad to hear they're working, and I really appreciate the help. The t nuts sounded like a great solution, but I didn't want to get my hopes up after all the trial and error.

Just ordered some of the t nuts you linked. I actually ordered some of the exact same but slightly shorter earlier today. I should have some of the 12mm and the 20mm length you linked delivered tomorrow.

I just took the drivers side valve cover off and broke one of the bolts on that side too. What I found interesting is that on both driver and passenger side, it was the lower bolt closest to the firewall that broke. Both bolts broke right at the head, leaving all the threads sticking out. Like others have mentioned, the rest of the bolts weren't on very tight and came out pretty easily, fortunately. I wonder if what happened is that over time as the gasket wore out and shrunk slightly, it caused pressure to ease across the other bolts, but somehow added pressure to the back bolt.

Anyway, thanks again for the input. Fingers crossed I've got this job sorted out by tomorrow evening!

 

[Landman2000]

Yeah, you may be on to something. It could also be the fact that the backside of those two bolts are exposed to the elements unlike the others. Good luck, I’m confident it will work out great for you.