I think I have resolved this issue, but thought I'd post it here to see if any of you have experienced this, and to warn about a potential life threatening issue.

Background: 2001 2WD 4D LT Purchased March 2009, 69,000 miles. No knowledge of previous ownership. Purchased from national dealer with so called ~100+ point inspection. Car appears fine for several months.


Summary:

At least one bolt holding the calipers to the hub on all corners except LF have worked out and caused the calipers to move and grind to the rim. Luckily when it occurs, it is driven slow and, all but one time, near home. The LF hub didn't want to feel left out and instead of brake bolts, one upper control arm bolt broke!


Fall 2010 The LR top bolt backed out and we were 100 miles from home. We could not go in reverse. Luckily the drive was almost all highway and we made it home safely. At the time it was dark and I did not know what was going on. The next morning I saw the backed out bolt (It did not fall out as it rested against the brake hose). I tightened it back up; however a couple weeks later I checked it and it was loose. Checked it about every two weeks. Loose. Applied Loctite. Fixed

Winter 2011. About 10 miles from home, going to a doctor's appointment, RR locked up while applying brakes exiting the interstate. The bottom bolt broke and/or fell out. Reversed to move caliper that was against the rim. Moved forward slowly and used very light braking, made it to doctor's office. After Doctor visit, removed RR caliper, placed suitable sized socket between brake pads, tied caliper to frame. Drove home slowly. Had to buy missing bolt. Loctite. Fixed.

Summer 2012 Noticed sound from LR. Observed that bottom bolt was gone. Recall Top was treated Fall 2010. Replaced bolt and treated with Loctite. Went ahead and treated the remaining RR top bolt. All four rear bolts treated. No problem since.

Fall 2012. Wife notices RF makes noise, then says she can not back up.
Yes. Top RF bolt is backed out, rests against brake hose. Loctite all four front bolts. No problem since. Did front brake pad replacement Fall 2013.
Removed caliper bolts to change pads instead of the mounting bolts.


Fall 2013.

LF rear upper control arm bolt snapped. Wife was about a block or two from the house about to begin a 100 mile journey on the interstate at 75 mph. Tire fell inward (Extreme negative camber). She got it home. I found the broken head from the rear bolt, confirming it snapped. Replaced both bolts. Had alignment done. I am weekly checking these bolts on both sides. All looks well.

We are lucky no one has been killed with this issue. All these bolts now have Loctite on them. No more issues, except needing Hulk like strength at brake pad changing time to remove the bolts.


I have never experienced this on any other vehicle that I've owned, in which I am probably pushing 1 million miles over 6-7 vehicles.

Has anyone else experienced this?

 

I've seen the odd broken or missing bolt, but very rare. With that many issues, I would suspect the wrong size or type of bolt being used, or improperly torqued. I have on my own Blazer forgotten to put a nut on(or didn't tighten it) a lower control arm bolt, and noticed it the next oil change. There was a little wear in the mounting hole, but nothing excessive. It drove fine and the bolt was still there 2k miles later.