Abstract: A vehicle braking system has a master cylinder, a first brake associated with a front wheel of the vehicle and a second brake (11) associated with a rear wheel of the vehicle, the master cylinder being connected to the first and second brakes in a common circuit. The second brake includes brake actuator (10) with a valve (30, 35) which will vary the rate at which fluid pressure is applied to the brake actuator (10) at a predetermined brake pressure, a spring loaded lever (50) acts on the valve (30, 35) to set the predetermined pressure at which the rate of application of pressure is varied and a linkage mechanism (70) varies to loading of the lever (50) to vary the predetermined pressure in proportion to the load applied to the rear wheel with which the brake (11) is associated.

Abstract: An internal shoe drum brake having a pair of brake shoes mounted on a back plate with double ended expanders located one between each pair of adjacent ends of the shoes. The expander has a strut assembly slidable within itself so that when the expander is operated the strut assembly transmits braking loads from one shoe to the other so that the brake operates in a duo servo mode. With the expanders arranged to operate vertically the weight of the shoes and acts against the strut assembly. In order to support the upper brake shoe and prevent the shoes moving off-center a variable length support acts between the upper shoe and the wheel cylinder. The support has a spring therein so that the support can resiliently collapse when the sheos move during duo servo braking.

Abstract: An internal shoe drum brake automatic adjuster comprising a strut extending between one brake shoe and a wedge, mounted between the strut and an abutment on a second brake shoe. The wedge is spring loaded to increase the spacing between the adjacent end of the strut and the abutment. The wedge has serrations thereon that engage with a pawl on the second brake shoe so that the wedge can only move to increase said spacing and not in the reverse direction. There is also provided a brake in which the strut is engageable with a mechanical lever pivoted to the one brake shoe. The brake is de-adjusted by moving the lever so that it no longer contacts the strut.