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Discussion Starter · #1 ·
Hello,

working on a GMC Express 4500 cube truck with dually.

the rear right caliper needs to come off so i can test it and replace it.

however one of the two bolts holding the caliper mounting bracket is impossible to get a ratchet onto??

its a 21mm socket i tried a 1/2 drive breaker bar it wont fit. I cant find any shallow socket at a hardware store and not a 21mm for a 3/8 drive either.

im stumped. I tried lowering the suspesnion but it doesnt realy make a difference the leaf spring is right behind the bolt with little to no clearence. How do you do this?? I could get a 21mm wrench instead but that gives littleforce and will most likelt strip it because they all come in 12 points not 6. WHY DO THEY NOT MAKE THEM IN 6 points??

please if there is someone out there that knows how to get those bolts off would be appreciated.
 

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For my 3500 cab&chassis, it's also pretty narrow between the spring pack and the brake parts. When I first got it, I had similar problems with the brake caliper brackets, needed to use heat (as the bolts should have red threadlocker on them), and used two wrenches hooked together to get them out (the 12-point closed end didn't strip them), and I wound up dropping the axle from the springs to torque them on. I eventually found a torque wrench that had a slightly narrower head, so it can just fit on the bolt head to torque it down without having to drop the axle.
 
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Discussion Starter · #3 ·
For my 3500 cab&chassis, it's also pretty narrow between the spring pack and the brake parts. When I first got it, I had similar problems with the brake caliper brackets, needed to use heat (as the bolts should have red threadlocker on them), and used two wrenches hooked together to get them out (the 12-point closed end didn't strip them), and I wound up dropping the axle from the springs to torque them on. I eventually found a torque wrench that had a slightly narrower head, so it can just fit on the bolt head to torque it down without having to drop the axle.
amazing, thank you for your input brother. I’ll be sure to use the 12 point and heat this time and hopefully find a 1/2 breaker bar or something with a smaller head or a shallower socket.
 

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...and if the socket/breaker bar just barely doesn't fit, consider modifying the socket and shaving some off the end of it to make it fit. They are more than deep enough, and it doesnt make it any weaker.
 
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Factory lock tighten is uhh. You need heat, and a long handle name brand 1/2 ratchet with a shallow socket for the upper bolt. And a maul.
 
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Once you break it lose, you have to swap to a wrench. Anything else will get stuck.
 
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Discussion Starter · #7 ·
Factory lock tighten is uhh. You need heat, and a long handle name brand 1/2 ratchet with a shallow socket for the upper bolt. And a maul.
thank you for your input, yes ill use a lot of heat for the thread locker altho i think im dealing with aftermarket torque specs on it from the last tech. Ill be sure to try to find a quality ratchet and socket for it next time. I got a flared wrench this time which i think will be better than using a 12 point.

thanks again
 
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