Bendix explains brake shudder
Leading brake manufacturer Bendix explains the reason for vibration through the steering wheel or brake pedal when you hit the brakes, and how this can be fixed.
Commonly referred to a brake shudder, vibration such as this arises as a result of issues with the brake discs, principally with variations in the thickness of the disc caused by rotor run out. Where the discs are unevenly worn, the brake pads only make contact with the flat spots on the discs causing vibration, commonly referred to as brake shudder.
Uneven wearing of the disc can be caused by a number of factors such as the brake calipers not opening correctly, the rotors being installed incorrectly or the proper bedding-in process not being applied following the fitting of new brake pads.
To correct the issue of shuddering it is necessary to identify the source of the problem.
Generally a shudder through the steering wheel indicates a problem with the front rotors whereas a shuddering or pulsation sensation through the brake pedal indicates a problem in the rear brakes.
Another common source of the problem is an uneven mounting surface on the face of the hub which can result over time through a buildup of rust and scale deposits. Such deposits should be cleaned off with some abrasive action and once clean, treated with an anti-rust product such as WD40 or CRC.
Where a brake disc develops disc thickness variation (DTV) the disc must be machined or completely replaced. Where it is identified that a caliper is holding a pad against the disc causing uneven wear, the seized slide pins should be eased out and lubricated with Bendix Ceramic High Performance Synthetic Lubricant or the callipers replaced.
Finally to avoid thermal shock after fitting new brake pads a bedding-in process should be adopted unless Bendix brake pads with the unique Blue Titanium Stripe are being installed for which no bedding-in is required.
“Torqueing down the wheel nuts evenly to the vehicle manufacturer’s specifications using a quality torque wrench is also extremely important,” said Bendix marketing services manager Ian Bott.