Well, this is just great.
So today I was under my '99 Prizm trying to swap out my AC compressor (it's different than the one in the Corolla), when I had two nasty surprises. The first was that the bolts were torx head bolts (stupid, stupid move GM), and the second, well, one of the torx heads was stripped. "Lucky" for me, it's on the bottom of the compressor, but still, only six or so inches away from the radiator.
I tried filing down two sides of the bolt (the head is perfectly round, the Torx star is recessed), but alas, six or so years of use, abuse and hideous Ithaca weather have taken their toll, and that bolt is pretty firmly in place. Granted, I did not file much off, but you get tired of that very easily.
The way I see it, I've got four options to take out this bolt:
1) Impact gun it. The T40 driver still grabs a little bit, so there isn't a perfectly round hole in the bolt, and there may be hope. Problem with this-- I don't have an air compressor, nor an impact gun, nor an impact driver, and I really don't feel like shelling out the cash unless I knew for certain that this would work. Also, I'd have to take out the radiator, which, while doable, won't be fun.
2) Screw extract it with an easy out. There'd be no way in hell that I'd be able to use an impact gun on it after I poke a hole in the bolt but, in theory, it should work. Plus, a screw extractor set is much cheaper than an impact driver. Problems with this-- I've never used one of these before, and I sure as hell don't want to learn on this bolt. Those things are brittle, and if it snaps, there's no way out. Plus, I'd have to drill a really straight hole in the bolt, and it's in a very awkward place, even with the radiator out. Also, this bolt is really long (5 inchish), pretty thin (6 mm, I believe, is what the threads into the block are), and quite torqued in.
3) File down the sides of the bolt more to make an impromptu hex head. At least I wouldn't ruin the bolt beyond all hope of recovery, and if I get it to a point where I can put a wrench around the bolt and twist, even just a little (I only needed about 1/8 of a turn), then the bolt will thread right out by hand. Also, I wouldn't need to take the radiator out, which is a nice plus to an otherwise sucky situation. Problems -- takes a lot of time, plus I doubt the bolt head was made to handle something like this.
4) Admit defeat and go to a mechanic around here so he can deal with it. I'll just get him to swap the three bolts for grade 10.9 metric hex heads, and love life afterwards. Unfortunately, he'll probably go for 3-4 hours of labor, charging me 150-200 in the process.
Do any of you know of any better way, or any good way to deal with this? I'm sure you can treat it as bolt head that just snapped off, but I've never had to deal with anything like this before, and I really don't want to mess anything up. It's also in such a hideous location! This day could not get much worse...
Any help would be greatly appreciated.