Getting ready to replace the front brake pads and rotors on my 2010 R56 Justa. This will be my first-ever diy brake job, so I'm trying to figure out what all needs to be done.

The Bentley manual says the following "self locking" bolts should be replaced with new:

- brake caliper to brake pad carrier, M8 (MINI #34116768190)

- brake pad carrier to steering knuckle, M12 (MINI #34116772428)

Round trip to the nearest MINI dealer to me is a full days drive, so I'll be ordering parts. Looks like the M8 bolts are about $5 each and the M12 are $4 - that's $36 for 8 bolts, plus shipping - and - I'm having trouble finding someone online who actually stocks both part numbers.

Does everyone actually replace these, and if so, can you buy them at a local hardware store, or should only genuine-from-the-dealer parts be used?

If the 'antilock' feature is why they need to be replaced, would a drop of blue Loctite serve the same purpose?

Obviously, if there is any real safety reason to replace the bolts, that's what I want to do, but if the recommendation is from BMW's paranoid lawyers rather than practical engineers, maybe not?

 

people who track their cars change pads frequently

do they use new bolts every time?

 

search those numbers and have a look --- they appear to be plain bolts pre coated with blue loctite.

 

Technically...You should not mix liquid tread-lock (loctite, Anabond, Perma-lock, etc) with pre treated bolts.

If you want to reuse the hardware, clean off all the original tread lock, then apply your own, and for the most part I believe "Medium" would be what you would need. (Generally Blue)

Your Tech Tip for the day.

Motor on!

 

Here is a front brake pad and rotor DIY. Part # 34116768190 here and 34116772428 here. If you have any questions, please don't hesitate to ask!

 

Yeah, I did that. They look like they are worth 75 cents to me, maybe a dollar - but not $5.25 each!

 

So, can anyone think of any other reason not to reuse the bolts except for the fact that the pre-treated self-locking feature of the OE bolts will be less effective the second time? (possibly MUCH less effective?)

I did think of one reason why blue Loctite might not be a good way to go: The Technical Data sheet from Henkel shows the regular blue Loctite (#242) has a service temperature range of -65F to 300F (-54C to 149C). I can imagine that nearby parts - like the rotor and pads - might get much hotter than 300F - but I'm not sure about the bolts.

Loctite does offer a High Temp thread locker, #2422 (medium strength), that is good up to 650F - so if I reuse the bolts, I will clean them thoroughly (wire brush plus solvents?), and then reinstall them with High Temp Loctite.

 

I think 99% of folks reuse them...might be worth having one handy in case you mess one up removing them.....
Often automotive books use somewhat generic "best practices" in many job descriptions....this maybe one of the cases. They say to change the bolts to keep the legal team happy.
If they look worn, stretched, or corroded, replace them...I doubt the local chain shop would replace them as a matter of SOP.

 

Pelican - thanks for the diy link - it looks very thorough, and the photos are great!

 

I've been doing brakes for MINI owners since 2004

I re-use the bolts

not ONE problem

(Haynes does not mention a need for new bolts btw .... or even loctite ...... nor any 'generic "change disk brake pads" DIY I've ever seen . . .Torque specks is a different story . . .)

 

My pleasure.

 

Yeah, I'm kind of thinking the Loctite may be optional, too. Seems like a properly torqued bolt should stay put unless there is something unusual about the application (excess vibration, rotational forces, etc.)

Like you, I have read a few diy articles, and watched a few videos, and none mentioned replacing the bolts - with the exception of the Pelican link posted elsewhere in this thread (a very informative step-by-step, actually). The reason I asked the question is because I thought the Bentley advice about replacing the bolts was somewhat unusual.

I'm new to the Bentley Service Manual, so I haven't yet got a feel for how reliable/practical it may be. Nor do I know what they use for their source material - did the recommendation to replace the bolts come from BMW/MINI, or somewhere else? I don't know. Does the recommendation from Pelican come from the Bentley manual, or somewhere else? I don't know.

So, my gut feeling was that the advice was a bit over the top - but I'm no engineer, and it's not the kind of thing I'd want to be wrong about. "This just in: a local shade tree mechanic died today when the brakes fell off his car."

Thanks to all!

 

I am no youngster. Not really old but old enough.
Have had at least 20 cars
Have done literally 100's of brake jobs DIY
Never replaced any bolts. (Except for the little Allen hold down bolt for BMW /MINI rotors ) ever
Tracked a BMW 128 and I can't even remember how many times the rotors pads calipers were off that car. Some times twice a day on week end events

Never had a problem. Ever. With bolts loosening up. Ever.

Rules. Never over tighten. If it has slide pins clean and lube as needed. Spring clips after a while loose tension. Replace those. Clean mating surfaces. Inspect everything

MOTOR ON !

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