Brake Caliper Bracket Bolts
 

I purchased a set of rotors and pads for the front brakes on my 1999 SL2 but when I got the wheels off I was only able to get one of the four caliper bolt pins out. The heads on the other three have now been rounded off due to the channel locks having absolutely no effect on them... So the next plan was to replace the entire caliper&bracket. But....

What size are these bolt heads???

I tried all of my metric as well as SAE sockets on these heads and none of them are a nice snug fit - all have a concerning amount of play when I put the sockets on. I am afraid to use any of them because with the amount of rust on everything in there I know I will round off the corners... Tempted to try an adjustable crescent wrench, but those are my last resort.

The heads are very thin too compared to other bolts making the possibility of stripping the heads even more probable...

yeah the vice grips is what I rounded off 3 of the four caliper guide pin bolt heads with...

A good set of chrome-vanadium sockets, preferably 6-point as mentioned earlier are essential if you want to avoid situations like this.
That being said I've seen both 10mm and 12mm heads on these bolts.

I'm not talking about the guide pin bolts, I'm talking about the caliper bracket bolts.

I believe these are 12 mm M12x1.5x30 bolts with 18mm hex heads.

If you've ever worked on your Saturn before, you know it is all metric ot torx..or I guess not. Leave the SAE s in the tool box minus the spark plug socket

If your metric 6 pt sockets are that loose on a fastener, then the fastener is already trashed and needs to be treated with care OR your sockets are worn and need to be replaced with a quality set per Jamnar..personally, vise grips do not count as trating them thrm with care. Douse thm twice a day with pb blaster for 2 days before attempting removal.

If you cannot break loose by hand, try an open end 18mm wrench and a rubber mallet, NOT a hammer to break it loose. Do not go nuts on it. A six foot cheater bar may help as well.

As a last resort, set your impact wrench extremely low and use an 18mm impact socket. Hit the trigger for 1 for 2 sec, then release. Your goal is to break it free from the rust. Then I go back to hand tools.

I will double check which socket was closest. It almost seems like a guy might have to remove the brake line in order to get any kind of an extension or air ratchet in there (at least for the passenger side). I did put a dose of PB blaster on them while I had the wheels off. I will probably keep hitting it with more PB blaster from time to time before I give it a go. The head does not look damaged at all - maybe the coating of rust is making it so the correct socket won't go over it. I might have to see if I can hit the heads with a wire brush or wire wheel. Thanks for the info here derf.

You don't need to remove the brake line to get at that one obnoxious bolt. If I remember correctly, you need to just use a 3in extension with a normal socket not a deep socket. A deep socket with no extension will also not fit. I think it doesn't quite line up straight but it does the job so be careful you do not strip it.

You should really use what is called a wobble socket for situations like this.

I have the impact wobble socket, just don't have the non-deep impact socket LOL - I'll have to see about picking one of those up. :) (<--- whoa, that is one of the scariest looking smiley faces I've ever seen)