defender hub seal


One standard method for measuring brake drums involves utilizing a brake drum measurement chart, which provides specific dimensions and tolerances relevant to different vehicles. Typically, this chart includes measurements such as the inner diameter of the drum, the total thickness, and necessary tolerances for both new and worn drums. By referencing this chart, technicians can determine if the brake drum is still within acceptable limits or if it requires immediate attention.
brake drum measurement chart

The wheel cylinder is central to the operation of drum brakes. It contains two pistons—one for each brake shoe. As hydraulic fluid enters the expanded wheel cylinder, it pushes the pistons outward, causing the shoes to press against the drum. Understanding this mechanism is crucial for diagnosing problems; if one side of the cylinder fails, it can lead to uneven braking and potential safety hazards.
drum brake line diagram
