Audi Audi S6 1999-2004 Brake System Bolt Torque Specifications

Overtightening brake caliper bolts can stretch or weaken the bolt, potentially causing it to fail later. It can also damage the threads in the caliper or mounting bracket. This could lead to brake failure, requiring costly repairs and potentially leading to a dangerous situation while driving. For example, if a caliper bolt snaps while braking, the caliper can shift, rendering the brakes ineffective.

Under-tightening brake caliper bolts means the components are not securely held together. This can cause the caliper to shift or vibrate, leading to uneven braking, premature wear on brake pads and rotors, or even brake failure. In a scenario where a bolt becomes loose, the caliper might bind or the pads may not apply even pressure to the rotor. This will cause reduced braking performance, and could lead to a significant loss of braking ability.

Proper torque specifications ensure that all brake components are held securely together while allowing for the correct operation of the brake system. Torque values are calculated to achieve the optimal clamping force, preventing component failure, vibration, and ensuring even force application. Correct torquing maintains the structural integrity of the brakes, and helps them function effectively and consistently in all driving conditions.

It is highly recommended to use new bolts when reassembling brake components, especially caliper bolts. These bolts are often designed to stretch slightly when tightened to their specified torque. Reusing them can compromise the clamping force and may result in the bolts failing under braking conditions. Think of it like this: if you stretch an elastic band once, it might be okay, but repeated stretching will weaken it until it snaps. The same principle applies to brake bolts.

Unless otherwise specified by the manufacturer, it's generally not recommended to use lubricant (like anti-seize) on the threads of brake bolts unless called for in the service manual. The specified torque values are designed for dry threads. Lubricating the threads will alter the friction and can lead to over-tightening and damage at the recommended torque setting, as the fastener will require less rotational force to achieve the clamping force.

Always set your torque wrench to the correct specification. Tighten the bolt in a smooth and consistent manner. Do not over-tighten - Stop applying pressure once the torque wrench clicks or indicates the proper setting is reached. If the wrench has a dial, be sure the needle indicates the set value. If you have a digital wrench, be sure the digital readout matches the set value. Verify the wrench is calibrated and in good working order prior to use for accurate torque values.