Abstract: A brake testing apparatus and method are disclosed which utilize a hydraulic subsystem as a stroke-limiting memory unit and as a position-holding means during the brake test sequence. The hydraulic subsystem is designed for inclusion in a brake testing means which performs a series of analyzable brake tests using a controlled force application system which applies the brakes under different, but predetermined, conditions in a series of successive brake applications. The stroke measuring memory unit uses the hydraulic subsystem to measure the distance of one brake application stroke and limits the next brake application stroke to that distance. The position-holding means utilizes the hydraulic subsystem to retain a given brake-applying position of the testing apparatus for the length of time desired in certain brake applications in the testing series.

Abstract: A portable vehicle testing unit which can be placed on the floor of the driver's compartment of any vehicle to be tested and which can be adjusted to the toeboard of the vehicle in such a way that a fluid pressure actuator mounted on the testing unit is almost in engagement with a vehicle control member, such as the brake pedal or accelerator treadle, so that the fluid pressure actuator will immediately move the control member upon build up of fluid pressure in the actuator. A feature of the design permits measuring the reaction force of the pedal (or treadle) against the fluid pressure actuator during the actuating stroke of the vehicle control member.

Abstract: A rate control system is disclosed for use in a brake testing apparatus which applies an automatically controlld force to the vehicle braking system being tested. The rate control system varies the rate of flow of hydraulic fluid displaced as the brake pedal moves on its brake application stroke, in response to the rate of increase of a feedback signal which represents the vehicle stopping force, or brake effort, measured at a vehicle wheel. Varying the rate of flow of hydraulic fluid controls the rate of application of the vehicle braking system during the test.

Abstract: A roller type brake testing device is disclosed which incudes two pairs of cradling rollers for supporting and applying a driving torque to two wheels of a vehicle such as an automobile. The testing device includes a pneumatic lift mechanism for selectively raising and lowering the rollers which engage the rear portion of the wheels and through which driving torque is applied to the wheels. The brake tester may further include an indicator such as a pressure gauge for displaying a measure of the weight of the axle supporting the vehicle wheels to guide the operator in applying the brakes to achieve a braking effort correlated with axle weight.