Hello Everybody,

Unfortunately I have a 2019 LCI M4 F82 which took a bit of a hit with the curb, it snapped the driveshaft inside the hub and broke the rear anti rollbar stabiliser , surprisingly all the arms and wishbones look okay and didn’t take a hit. After replacing the drive shaft and stabiliser along with the rear wheel, I noticed that my handbrake is all of a sudden not working, I put the car back on the ramp and found the rear driver side wheel which took the impact’s hand brake cable is more lose than the other side. Anyway my biggest problem is the brake on that axle. When pressing the brake after the accident, the brake pedal feels spongy like it needs bleeding. I bled the system but didn’t solve my problem.


I took it to a MOT shop and placed it on their brake roller, all the other brakes function perfectly fine except that brake on the axle that took the impact. It starts to brake the wheel after the peddle becomes spongy, while the brake peddle is hard and stiff no pressure goes to that axle. Also I realised while driving the car at higher speeds the brake peddle is stiff then starts sinking but if you are creeping forward the peddle is soft and spongy. When the car is stood still the peddle is stiff. I checked the computers and only had stored fault for wheel speed sensor which was cleared and never returned. I also inspected the calliper which physically does not look damaged nor does the brake line. However what I noticed in the calliper is that one of the pistons could be pushed back with my fingers (I could push the pads back) which is not the same on the other axle that didn’t take an impact.


Please help? Any ideas?