Broken caliper bolt - Page 4 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

RandallNeighbour · 05-18-2015, 09:50 AM

OP: You're lucky you didn't completely strip out the hub the way I did with my top caliper bolt removal. Took me nearly an hour to remove them slowly moving back and forth and the receptacles were totally smooth when I was done. No choice but to drill them out bigger, put in a helicoil, and go back in with a new bolt. Ugh!

My car was purchased and driven a few winters in Salt Lake City, Utah. I'm betting this is where the problem began.

CoBeerToad · 05-20-2015, 07:05 AM

I think I know where I might be having an issue. I broke my socket when first attempting this so I've been using a long-ish allen wrench. When I put my jack handle on it for more leverage, all I am doing is flexing the wrench.
I'm gonna buy a breaker bar (because I've given up trying to find mine in my garage) and a new socket. Then I should be able to beat on it with a BFH and get some results because right now, I can't get this bolt to spin either way.
Memorial weekend is coming up fast and I still have 3 rotors and calipers to paint. I'm sure a rush paint job is exactly what I need.

Mark_T · 05-20-2015, 07:23 AM

Suggest you buy a Snap-on, Mac or other really high quality socket. This isn't a job for HF crap.

CoBeerToad · 05-20-2015, 08:20 AM

Anyone know the size / type wrench / socket I will need for the new caliper bolts? Might as well get both while I'm out and the new ones don't arrive until Friday-ish.

woodsman · 05-20-2015, 11:22 AM

Forum member JP previously posted that Porsche changed the bolts ( to triple-square?) because of the high torque value (130 ftlbs?). I cursed Porsche when one of my bolts stripped on it's way out but then realized that the lightweight choice of aluminum for the hub is the culprit (collateral damage). I think these bolts are often over-torqued and the threads stretch hence the problem when it's time to loosen them. A better solution is one that Tarret offers utilizing threaded rods and nuts. Once the rod is installed it never needs to come out.

CoBeerToad · 05-20-2015, 11:58 AM

Wish I would have thought of that earlier. Their site shows $125 per axle though. A smart person could probably find these cheaper.

I believe it's a Torx head. I was too impatient and bought the allen head and breaker bar from Harbor Freight. They're having a big sale on Friday so I'll buy the Torx head then. I know they suck, but I bought the impact socket and I don't see how I could possibly break that.

tommy583 · 05-20-2015, 12:04 PM

The new bolts will be size 55 torx. The torque for the new bolts should be 63 foot pounds.
Don't try to twist that bolt too hard if it doesn't want to turn. That's how I snapped the head off.

CoBeerToad · 05-21-2015, 08:38 AM

Got about one full turn and there went the head. Put two nuts on it and got about two full turns and snapped the bolt again.
So I got it put back together enough to turn the car around and I'll hit the other side. If all goes well, I'll nurse it to the shop to pull that bolt out. If I break another one, then I get the luxury of being on a tow truck for the first time.

tommy583 · 05-21-2015, 12:07 PM

I drove my car to the shop with a broken head on the top bolt, no problems. If it was the bottom bolt or one of the rear brakes then I'd think you need a tow. My shop couldn't get the bolt out and wasn't willing to drill it out on the car. I ended up just getting a new (used) hub from Woody (itsnotanova). I hope your shop has better luck.

woodsman · 05-21-2015, 02:31 PM

Drilling a bolt out is very easy once you've cut/ ground it off as short as possible as long as 1: you use high-speed- steel drill bits and some type of oil to spray on the drill as it works in order to aid the metal cutting and cooling 2: Use a pointed punch to establish a small divet/crater in the center of the bolt to be drilled. This because the hole needs to be centered in the bolt. 3: Use a center-drill to start the hole. A small drill (1/16") bit can be used instead but center drills are cheap 4:Use multiple drill bit sizes for holes over .25". In this case I'd use 1/8, 1/4, 3/8 and final size. It may sound like a lot but once the first hole is drilled each subsequent pass is easier. This stepped approach spreads the workload out and allows the bits to work most efficiently. 5: Apply 'persuasive force' to the drill. Too much produces more heat. Let the bit work. A little smoke is OK, a lot means slow the drill speed and/ or less pressure. Blue chips mean you're toasting (annealed/ softened) your drill bit because it's too hot. 6: The largest drill size should be the 'tap drill' size. Smaller is better because too big means you're removing the threads in the hole. A couple of sizes smaller than tap-drill size (1/32") will leave enough of the bolt to crush and twist out in one piece.

CoBeerToad · 05-27-2015, 09:54 AM

Got the passenger side all done with no problems. Brought the car to the shop to see if they could remove that bolt and they couldn't, so since the carrier is otherwise jacked I'm going to try drilling it out. Can't hurt. I'm moving in 17 days, so nothing like a little bit of pressure to get the job done right.

clickman · 05-28-2015, 08:04 AM

After reading this thread I think I might change out my rear bolts proactively. I don't think they've ever been done on my car (the fronts were done in '08).

I had the passenger side ones out a couple days ago to check the park brake, and noticed some corrosion / slight reduction in thread diameter along a short part of the length. I put them back in but think it's time.

I notice Pelican sells silver anti-seize to go along with them. I have copper. Is copper a problem in this application?

Timco · 05-28-2015, 08:23 AM

Quote:

Originally Posted by RandallNeighbour

OP: You're lucky you didn't completely strip out the hub the way I did with my top caliper bolt removal. Took me nearly an hour to remove them slowly moving back and forth and the receptacles were totally smooth when I was done. No choice but to drill them out bigger, put in a helicoil, and go back in with a new bolt. Ugh!

My car was purchased and driven a few winters in Salt Lake City, Utah. I'm betting this is where the problem began.

Yeah, I know, blame it on the Mormons....

I'll have you know our roads are very smooth, and we use a brine solution not real salt unless it's super bad. This solution is applied before it snows and is very effective.

I'd say it's very rare for a car to get all salty and nasty. Maybe in Denver...