the bolt that holds my seat down to the floor , the head of the bolt broke off how can I remove the bolt?

 

The normal method is get a cobalt drill bit a bit small than the bolt diameter, drill a hole into the center of the bolt shaft and then us a, easy out to get the shaft out.

However, usually when the bolt shaft is seized enough to break the head off these hardened bolts, you end up snapping the easy out in the hole you just drilled.

I am not sure the bolt hole design for the seat bolts in the floor. Depending on this will depend on whether you might end up drilling out the bolt shaft and tapping the hole to a larger size or if you drill out the bolt shaft and can use a rivnut.

This is the non fire way of fixing.

The fire method is drill the hole in the shaft, strip the interior out and remove the carpeting and any sound deadening in a two foot radius of the broken bolt. Torch the broken bolt and the hole until it starts glowing red and then use the easy out. The heat usually lets the bolt shaft come out without breaking the easy out.

The fire method means having a couple of fire extinguishers at your fingertips while you are torching. And I would not recommend this method in your garage just in case the car does go up. I really don't know if the car undercoating is fireproof or whatnot.

 

Excellent ideas. Did the bolt break off flush with the floor? If not, some penetrating oil (and then some time) and a pair of vise grips may do it. Otherwise, TomCat's got the right idea.

 

I've had bad luck with easy-outs. If they break, you're really sunk.

I got a set of reverse drill bill bits last year @ Harbor Freight that work better. Ideally, the heat from drilling will ultimately back the bolt out. Worst case, you'll end up drilling through it, grab the next size up, try again.

 

I like you method.

I too have not had luck with easy outs. And they are harder to drill out then the bolt itself usually.

 

Is it broken off flush?

Penetrating oil, followed by some loving with a center punch and hammer to break things loose.

If there are some exposed threads above the floor, is there enough to grab with a vice grip? If not, can you cut a slot in the bolt with a Dremmel tool? Then use slotted screw driver to unscrew. But first the PB Blaster/Kroil and center punch...