Top tip for driving safety

[Topblag]

Check your brake caliper mount bolts frequently.

I was out for a burn in my cabby last night and came to a very quick stop from about 60mph about 1.5 miles from home. Bottom bolt on the OSF caliper mount disappeared and the caliper pushed out and used the Alpina 16" front rim like applying the handbrake to the inside of your rear disk.

I thought it was an full engine and timing failure.

I had visually inspected the brakes a few times since I last had the caliper mount off, but not the tightness of the caliper mount bolts.

For clarity, the bolts were genuine parts which were tightened as it's always something I double check after Daimlerman's episode.

[JF008]

Hi buddy, could you put a picture up? sound silly but what bolts? Also what episode? There you go, 3 questions in a row I'm not in the loop

[Topblag]

I'm struggling with pictures.

The same thing happened to Daimlerman, allegedly after he fitted stainless steel bolts.

Two bolts which hold the caliper and mount assembly to the strut.

[Speedtouch]

Ideally, they should be loctited in.

I notice some new brake parts come with bolts that have some gloop on the middle part of the threads for this purpose.

[rich318i]

Yep they go bang BMW parts bolts and nuts crap now days

[daimlerman]

The same thing happened to Daimlerman, allegedly after he fitted stainless steel bolts.

Kos claimed,wrongly,that I fitted stainless caliper bolts.


For the umteeth time,I FITTED BMW CALIPER BOLTS!

[Topblag]

Sorry Malcolm, I did say, "Allegedly"

[initial_g]

Always stick some loctite on the thread and torque up too, shouldnt happen then.

[B7]

Always stick some loctite on the thread and torque up too, shouldnt happen then.

As per OEM.

The problem occurs when you use the old bolts without thread locking gear.

[Kos]

The same thing happened to Daimlerman, allegedly after he fitted stainless steel bolts.

Kos claimed,wrongly,that I fitted stainless caliper bolts.


For the umteeth time,I FITTED BMW CALIPER BOLTS!

I didn't claim, I was told

[daimlerman]

Second photo,centre of shot,shows the drilled out remains clearly seen in place in the first photo.

THAT IS NOT A STAINLESS BOLT,IT IS A BMW SUPPLIED BOLT.

What probably happened to me was that the lower bolt was not torqued up properly and unwound it's self and fell out,allowing the caliper to swing up and destroy not only the wheel rim but slice through a stainless steel braided brake hose and mangle the brake back plate.

Front caliper bolts should be torqued to 80 ft lb.
Rear caliper bolts to 60 ft lb.

One can have the shinyest engine bay possible,but it's worth bugger all if a brake caliper falls off and you destroy your pride and joy!

[Jesus325iTouring]

Tell you what it's you lot using torque wrench's and all that, i'll admit, I do not own one, never owned one and never torqued any bolts, just used the "that feels about right" technique.And as for thread lock, well, the same, never used it. Seems to have worked for me for 25 years

Pikey mechanics FTW

[Speedtouch]

I recall there was a seized front caliper bolt on my brother's Renault Clio, when I changed all the brake pads last summer.

The front calipers were meant to be of the sliding type, but neither did, which had caused the inner pads on both to wear right down.

Eventually managed to wiggle the offending bolt out using a blowlamp, and various tools to extract it, then he had to take it to an engineering works next door to get the bolt straightened out, as Renault wanted silly money for a new one.

Finally managed to get it all back together in the same day, and it's been fine ever since.

[Brianmoooore]

Second photo,centre of shot,shows the drilled out remains clearly seen in place in the first photo.

Correct bolt is 10.9 grade, and not that easily drilled out. Sure it wasn't an 8.8 that got in there by mistake?

[daimlerman]

Second photo,centre of shot,shows the drilled out remains clearly seen in place in the first photo.

Correct bolt is 10.9 grade, and not that easily drilled out. Sure it wasn't an 8.8 that got in there by mistake?

I thought that I had done well to drill the bolt remains out without mangling the thread!

The broken one was the same one that came out when the brake was stripped for re-building,replaced by a pair of new bolts after this episode.

So IF the wrong grade of bolt was fitted,it was before I purchased the car.

[bmw9818]

use loctite and just tighten it up proper, never really used a torque wrench for those,