Abstract: An air disc brake for a road vehicle is proposed, having a mechanism for causing retraction of the brake pads when the brakes are no longer applied, to avoid parasitic drag caused by continued contact of the brake pads against the brake disc. The proposed mechanism includes a pin located in a fixed position relative to one brake pad, and extending through an aperture in the other brake pad. A coil spring is supported on the pin, and pushes the brake pads apart. Where the pin extends through the aperture the extent of the pin provides an indication of the wear state of the pads and disc, which is visible through apertures in the wheel rim.

Abstract: Sealing means are disclosed for preventing the ingress of water and dirt between a brake caliper and the carrier guide pin. At the end of the guide pin facing away from the brake carrier, a retaining clip holds a sealing bead of a sealing boot at least partially within an axial bore of the guide pin. At the end of the guide pin which faces towards the carrier, a sealing boot is provided seated on a ring which in turn is attached to the caliper. The other end of the sealing boot is attached to the guide pin, in a space between the guide pin and the ring. The sealing means at either end are compact, and provide effective sealing where there is not enough space to provide known sealing means.

Abstract: A disc brake (10) of the type including a pivoting lever having eccentric journals which act on a pair of tappets is disclosed. The tappets are adjusted in length by rotation, and each tappet has a tappet gear (22). A centrally located intermediate gear (24) is provided between the tappet gears to form a gear train, synchronizing the rotation of the two tappets and therefore ensuring that they remain the same length. The centrally located intermediate gear (24) includes a socket (26) for receiving a centrally located adjuster. The adjuster may be installed and removed from the disc brake through an aperture at the rear of the brake caliper, without any substantial disassembly of the brake and without de-synchronizing the tappets or even interrupting the gear train between the tappets.