Are the torx retention bolts for the brake rotors self-locking, or just cursed? I have a 2009 Clubman S, and I'm doing a brake job and having a very hard time getting these blasted bolts out. Each one has required heating with a torch, followed by a soaking with penetrating spray. Even then they were really difficult to remove. The new bolts are equally hard to insert, requiring me to block the rotor from rotating while I tightened the bolts down. The threads in the hub are clean, so these bolts feel like eccentric self-locking bolts. These bolts are from the dealer, and marked "Boesner 10.9". These aren't really grade 10.9 bolts are they? Any good "normal" replacement bolts?

 

They will be very tough coming out, heat and rust play a big role in that. However they shouldn't be that hard going back in, I could put mine back in by hand.

 

This is what is so confusing, it was about as tough putting in the new bolts as removing the old.

 

if you must fight to put the bolts back in ... I suspect the threads are damaged . . .


you do realize that the ONLY reason these fasteners are there are to hold the rotor position until you bolt the wheel on?


IME getting one out the first time usually required blocking the hub from turning and ensuring I held the wrench (with the torx head) hard to the hub because it REALLY wanted to slip and damage the fitting . . . and I always use a good PB Blaster or WD40 soak if it is a car I'm working on for the first time.


when you put the retainers back in ... use anti-seize

 

when you put the retainers back in ... use anti-seize

^that

They are usually hard to get out, but not to put in.

 

use anti-seize ,

...always . Use a T50 torx socket. I have seen these get chiseled out. Sometimes drilling the center and then using a screw out tool works.

Once they have anti seize on the threads they come out in the future no problem.

http://www.ecstuning.com/Search/SiteSearch/07136772426/



thanks

 

To answer the original question - they are cursed!

 

To add to what Eric said "use anti-seize" and don't tighten them down much at all. They aren't going anywhere.

Thanks to this forum I learned early on about these, used anti-seize and checked them every tire rotation. Then the dealership did some work on the driver front, put that bolt in so tight I couldn't get it out and I messed up the head trying. Had to drill it out, so I could get the rotor off, but I wasn't able to get the entire bolt out.

The mechanics at the dealerships should be forced to work with nothing but hand tools until they learn how to torque fasteners to spec! This could so easily be avoided.

 

They are not "cursed". If you look at the threads of the screw, they are not circular in shape, more of a rounded triangle. So yes they will feel hard to break loose and remove as well as to re-install. This is done for two reasons: 1. make sure the screw doesn't come loose 2. make sure a new screw is always used when replacing rotors.

I just went through changing all four rotors on an 08 Clubman that had close to 30K miles on the rotors (best I can tell) and, even though we did snap a T50 bit on the first rotor, using a breaker bar and lots of PB blaster, along with knocking on the bolt to "wake it up", all of them came out without much fanfare. They're only torqued to about 20 ft. lbs. so it's not like they have a torque holding them in. It's just the unique shape of the bolt.

 

Impact driver with a t50 bit will be your friend also in the future

 

i watched a tech at the dealer remove a set of front discs

he used a 3/4 inch pneumatic impact driver! ... never even tried hand tools

they came right out

 

I used an impact gun on mine.

But believe me, I probably muttered every curse word in the book before I finally said screw it, and stuck a non-impact rated torx socket on my impact gun (I did don full facial protection in the event the socket exploded).

 

Thanks, this explains a lot of my problem. I thought the threads looked odd. This was the first brake job on the car since new, so these bolts were installed at the factory. Seems like overkill to me. I've done zillions of brake jobs on older cars, and never had a problem with these retention bolts backing out, so I'm not sure why they decided to go this route. Removal was a thrill, it was an escalation from torx bit + hammer, to torch and penetrating oil, to air chisel. The air chisel eventually won, but the bolt put up a heck of a fight! Next time I'll try the impact driver, otherwise I'm just going to either drill the head of the bolt out if it sticks, or whack the rotor from the back with a BFH and break the rotor off the bolt.

 

Nice.

This was mine after I managed to get it cut out:

 

Ha! I look forward to the challenge!!!

Searching for impact rated T50 next

 

I can tell you how to get them out without all this sturm and drang - tighten the bolt slightly first to break it loose, it will then come right out.


You can do this by hand with a breaker bar and socket, or use an impact wrench.....just give it a short burst till it moves ever so slightly, then it will come right out.


Try it, you'll be surprised how well it works!


It doesn't hurt to use a good penetrant first, but it's not necessary. BTW, WD-40 is not a good rust penetrant, just FYI.

 

I had similar problems the first time I changed my own brakes on my R53. I ended up taking it to a shop and the tech used a manual impact driver and a hammer to get the job done. I've always used anti-sieze after that.

 

Good idea, and a great all-around tip for loosening stuck bolts. I tried this and it didn't help in this instance. Self-locking rotor retention bolts are really the answer to a question that nobody asked.

 

I just use a Dewalt impact screwdriver with a bit. They come right out...


As for rust penetrating oil...


AeroKroll> 50/50 mix of ATF /Kerosene>PB Blaster> Liquid Wrench> heat and melted candle> >>> WD-40? it removes stickers, grime, and displaces water (original intended use). But that's about it...lol

 

Must be all you snow people with salt as I have never seen this problem here in TX, they always come out easy.

 

It was tight for me but a regular 3/8" hand ratchet and T50 tip and it came out.