How to remove really small broken bolts?

Attempted to do the diff breather mod to my 03 DCSB but 2 of the 4 bolts that hols the filler cap in place broke off due to rust. Previous owner had the body lifted and I can tell that they stripped the heads on those bolts trying to get the piece back in. Anyone have a suggestion of how to get them out? I don't have a picture but these bolts are very small and there isn't much of a head left sticking out of the hole for me to grab onto with a vice grip or anything.

I read online that easy outs work greak but I think these bolts are too small for that to work. I also read about using a dremel and cutting a slit into the broken bolt and using a flathead to remove it. I have lubed it with PB blaster and if I were to use the dremel I would definitely cut into the sheet metal and part of the threads on the truck...

I would like to get that mod done this weekend. but damn those 2 broken bolts are a pain in the butt. The other 2 bolts are still on there as I wanted to give them time to soak in PB blaster so they wouldn't snap like the other 2.

 

These are too small for easy outs, so your only option would be to drill them and make new threads with a tap

Another option would be to weld a nut to what is left, but you say that there is not much that sticks out of the hole.... so that's not possible

 

How would I drill them out? match the hole size with a drill bit and then just create new threads once everything it gone?

Sounds like maybe the dremel might be a good choice since I may be able to save the threads compared to completely drilling them out and re threading them.

 

yeah, use a drill bit the same size as the bolt. Unfortunately, this will damage the threads, hence why you'll need to re-thread the holes

well, you can try the dremel thing, but I am not sure it will do much since they are seized due to rust

The remaining bolts, tap on them with a hammer before attempting to unscrew them. Tapping helps to break the rust in the threads. If they don't want to come out, tap on them again for a while. And yeah, soak them in PB blaster

 

If I can get those 2 out I may just replace them with stainless bolts and leave it be

 

These bolts are not that long and the captive threads don't seem that deep. So you shouldn't have much to drill through. I'd be impressed if they were 8mm long.

 

yeah, that's what I did, me too. Replaced them with stainless bolts.

It was a pain to remove them, so no way I'd fight with them again in the future! Stainless and no headaches anymore!

btw, when you don't replace with stainless bolts, put some grease on the bolt before screwing it in. The bolt wil never seize in the threads (from rust or foreign material)

 

Left handed drill bits work

 

So maybe they sell a really small left hand drill bit? Would that back it out?

 

They do and usually work

 

Heat is youre Uncle! Use it. Get easy outs that are small enough and torch that sucker till it gets almost orange, it will come out! I saved a KTM crank for a customer this way as I always do, it was way worse than youre situation, the crank bolt was locktited with GREEN!, omg bolt snapped off removing the front sprocket. I drilled out the 1" wide crank bolt and it was flush with the crank, put the heat on it and the bolt came right out.

 

Heat and filler neck don’t mix

 

Spray them with penetrating oil and let it sit (give it atleast a couple hours). Use LEFT handed drill bit to drill them out. Drill slow and keep the bit straight to the bolt shaft.

 

Nevermind somehow I though it was the breather on the axle.