Steering wheel shakes under braking

[eight~deuce]

Under heavy braking my steering wheel violently shakes, usually after driving hard. During normal city driving everything is fine, but when I start driving more aggresively and get on the brakes hard, the steering wheel shakes violently.

It might be related to temperature somehow, because after braking hard even light braking shakes the wheel

Any ideas on why this is happening? My CAB's are fine, so could it be warped rotors? Would warped rotors only shake the car when they get really hot? I've searched but couldn't find much

[mrcheezle19]

my first guess is warped rotors, get your brakes checked and they will let you know. You can get them trued which means they will make them smooth and even again if there is enough meat left on them. I would personally just buy new ones since rotors are cheap for our cars.

[dnguyen1963]

Normally when a rotor gets warped it stays warped so if you are experiencing shaking only when it gets hot then I would suspect you have air in your lines or your brake fluid is contaminated with water. Replace the brake fluid and bleed the system.

[jlevie]

You will usually feel a pulsation from warped rotors in the brake pedal, but not always. Uneven pad deposits, from overheating of the pads is much more common than warped rotors, but that usually causes problems with with light braking. It is easy enough to check for warped rotors with a dial indicator.

Any wear in the tie rods or control arms can cause this, as can work shocks or wheel bearings.

[dnguyen1963]

I would think that wear in tie rods or control arms would cause shaking at any temperature. OP reported that he experienced shaking only at hot temp.

[jlevie]

I would think that wear in tie rods or control arms would cause shaking at any temperature. OP reported that he experienced shaking only at hot temp.

Well the OP isn't telling us enough. Like what brake pads are on the car or if the car has been brought to a stop with the pads overheated.

I've only seen once case of warped rotors. Their behavior was worse when the brakes were used hard on track, but they had milder symptoms when cold. The dial indicator proved that one the rotors was warped.

[dnguyen1963]

Yeah, BMW rotors are the best in the world. I am not going to replace mine until I have to.

[eight~deuce]

Well the OP isn't telling us enough. Like what brake pads are on the car or if the car has been brought to a stop with the pads overheated.

I've only seen once case of warped rotors. Their behavior was worse when the brakes were used hard on track, but they had milder symptoms when cold. The dial indicator proved that one the rotors was warped.

I don't know what pads or rotors are on the car, they are the ones that came on the car when i bought it this year. They feel oem spec though, i don't think they're aftermarket. I have brought the car to a complete stop with hot brakes

[eight~deuce]

Normally when a rotor gets warped it stays warped so if you are experiencing shaking only when it gets hot then I would suspect you have air in your lines or your brake fluid is contaminated with water. Replace the brake fluid and bleed the system.

This sounds possible, my brake fluid really needs to be changed. I didnt know that could produce these symptoms. I'll change the fluid soon and report the results.



Thanks for the ideas guys