Broken rear seat bolt -- how to get the broken piece out?

I was re-installing my rear seat today when one of the smaller (rear-most) bolts broke off, leaving approximately 1/4" of the bolt still screwed into the chassis. Very little of the bolt is sticking out, probably not enough to grab even with needle-nose pliers. How do you remove the broken screw piece when this happens? I was thinking that a very small drillbit might help, but wanted to get more feedback before doing anything that could exacerbate the situation. Obviously I need this socket cleaned out so I can properly bolt the seat in. Thanks!

You will need what is referred to as an E-Z out or broken screw extractor, available at automotive parts or tool or hardware store. First you drill a small hole into the center of the broken screw about 1/2" deep or straight through if needed. Next, insert the E-Z out which is basically a very coarse , left-hand threaded screw. Tap it in slightly and loosen normally.

Personally, these have never worked that well for me(usually they break off in the screw, now you have a HARDENED EXTRACTOR busted off in your broken screw or bolt ....ARRGH!) UNTIL I found a superior product that I believe is made by LISLE tool co. It is NOT SPIRAL threaded, but instead has ribs that run parallel to the screw body. Drill the hole with the properly sized drill bit, pound in the extractor and remove the screw normally.

I've used these more than once to remove broken air injection manifolds on G.M. cars (if you ever had to do this, you know it's a be-otch) and they worked every time.



A couple of tips:

Drill as close as possible to the center of the screw. File the top flat and centerpunch, if possible.

Drill slow and maintain control, don't let the drill bit wander off- center or you will run into the weld-nut threads.

If possible, use a propane torch
( now you should have a fire extinguisher or water handy)
to heat the area to help break the mechanical interference between screw and nut, but be careful not to set paint, carpet or undercoating on fire

(before and after using a flame to heat, check the opposite side of the work area to make sure you don't ignite anything ).

The other options are to just drill it out oversize, straight through and retap with the next larger size tap.

When drilling through ALWAYS check to see what's on the other side of the work surface. You don't want to drill a brake or gas line or tank.

Finally,
if you plan on removing a bolted part frequently, I'd recommend using an anti-seize compound on the bolt.

Good luck, and remember, we're all counting on you .

Thanks! Those are some great tips. I think I'll try the screw extractor tip first. Hopefully I can find the better extractor you mentioned.

You can also use a small grinder or rotary tool to carve a flat or philips opening into the top, if you want to just try a screwdriver to get it out.