850 The pin that attaches the disc to the hub is broken

Post by **manovlov** » 02 Aug 2021, 09:33

Hy Buddies,
The 10 mm pin that fixes the brake disc to the hub is broken into the hub. Each time i brake i feel the disc moving till the brakes platelets are taken.

What tool do you recommend me to extract this screw ?

Drill bit 4,2 mm

: Capture d’écran 2021-08-02 à 17.30.17.jpg (41.43 KiB) Viewed 883 times

and then, this one ?

Manov.

Post by **volvolugnut** » 02 Aug 2021, 09:39

Left hand drill bits (cut in opposite of normal direction) are recommended for extraction work.
volvolugnut

Post by **manovlov** » 02 Aug 2021, 09:40

Which size do you mean for that 10 mm bolt , to you ?

Post by **misha** » 02 Aug 2021, 10:16

Rotor can't be moved when you apply brakes because the wheel lugs/bolts...all 5 of them are keeping the rotor in place.

That guide pin is preventing the rotor to be moved when wheel is removed from the car.

Some factory rims like Persus have a blank space on the inside to accept that guide pin.
There is no other way to mount the wheel on the car if you don't aim the guide pin and opening on the rim.

They are usually a 10mm.

Post by **foggydogg** » 02 Aug 2021, 10:29

I agree with @misha , the rotor should be captured by the wheel and lug bolts. People who use some aftermarket wheel have to take those little pins off anyway.
If you can get the rotor off, maybe you can get a grip on the nub with some locking pliers ?

Post by **manovlov** » 02 Aug 2021, 10:53

Ok Guys. I understand. So from where could come this feeling of something moves when I activate brakes (front wheels) ?

Post by **wizechatmgr** » 02 Aug 2021, 11:29

Check your front struts and the rotors for warpage. Could just be warped rotors which will give you a surging feeling, or the front end of the car is taking a dive due to bad struts/springs.

Did you bleed the air out of the brakes while/after doing your work?

Post by **manovlov** » 02 Aug 2021, 11:34

All the suspension is new, rods, shocks, springs only OEM. Rotors have 2 years. Maybe the brake pads are "glazed"? I will check them tomorrow. I will replace the steering rack fluid, so it will be the perfect occasion.

Thanks for the help.

Manov.

Post by **manovlov** » 02 Aug 2021, 11:37

foggydogg wrote: 02 Aug 2021, 10:29 I agree with @misha , the rotor should be captured by the wheel and lug bolts. People who use some aftermarket wheel have to take those little pins off anyway.
If you can get the rotor off, maybe you can get a grip on the nub with some locking pliers ?

What surprises me is how the hole parts are moving, brakepads, discs. It always seems not normal to me....

Post by **misha** » 02 Aug 2021, 14:48

manovlov wrote: 02 Aug 2021, 10:53 Ok Guys. I understand. So from where could come this feeling of something moves when I activate brakes (front wheels) ?

Inspect front suspension parts....tie rods,bushings and ball joint on control arms....brake calipers and pads.