Abstract: In a braking unit of the SAHR type comprising a braking pack with disks and counter-disks, a resilient system for compressing the pack with a braking load sufficient for parking braking, a first hydraulic system for exerting on the resilient system a contrary load sufficient to cancel out its effect, a second hydraulic system acting on the pack to compress it with a braking load sufficient for service braking, both hydraulic systems share a single piston acting on one side on the pack and on the other side on the resilient system.

Abstract: A brake actuator includes an electric motor, a conversion device for converting the rotational movement of the electric motor into a linear movement and a hydraulic transmission for transmitting the linear movement of the conversion device to an adjusting piston of a brake. The conversion device includes at least two adjusting elements which can be driven by the electric motor and by way of which the at least two hydraulic pistons of the hydraulic transmission can be operated independently of one another in a hydraulic chamber which can be selectively connected with a reservoir.

Abstract: A boom hoist system for supporting and adjusting the position of a lifting crane gantry is provided including a drum, a drive system, and first and second braking systems for selectively stopping rotation of the drum. The boom hoist system operates independently from crane mechanical works and the first and second braking systems may include sensors for automatically engaging when specified conditions occur in order to prevent a hoisted gantry from falling uncontrollably in the event of a hoist system malfunction or failure.

Abstract: Piping associated with interlocked brakes for front and rear wheel brakes is to be simplified to improve maintainability and provide a brake system suitable particularly for a two-wheeled motor vehicle satisfying racing specifications. A braking system includes hydraulic brakes with three hydraulic systems which are a lever hydraulic system for a front wheel brake, an interlocked hydraulic system for a rear wheel brake and a pedal hydraulic system. A pressure sensor detects a hydraulic pressure in the lever hydraulic system and outputs the detected signal to a control unit in the interlocked hydraulic system through an electric wire. The control unit controls the operation of a motor, thereby causing a hydraulic pressure to be developed in a submaster cylinder, which hydraulic pressure is fed to the rear wheel brake through a control valve.

Abstract: A process and a system for briefly stopping a vehicle which utilizes a secondary brake circuit. In the present case, the problem is to be solved that the vehicle operator must exercise high brake holding forces in a stopped condition and, because of a constant slip stick effect, there will be a brake creaking. This object is achieved in that a braking intervention is carried out by an external power or secondary brake circuit when the vehicle speed falls below a defined limit value and an active braking intervention by the vehicle operator takes place beyond a given first rate, the operation of the brake pedal being continuously monitored by the vehicle operator.

Abstract: A motor vehicle parking brake system which is operated by non-muscular energy, includes both by a hydraulic pressure generator and by an electromechanical control unit. A control unit ensures that the switch between hydraulic and electromechanical operation is made as a function of the operating state of the vehicle.

Abstract: A plurality of electrical fluid pressure control valves or a plurality of groups each comprised of a plurality of electrical fluid pressure control valves are operatively associated with respective power supply replays. The electrical fluid pressure control valves and a plurality of electrical switch valves are connected in parallel to a power source. A plurality of failure sensors are associated with the respective electrical fluid pressure control valves or the respective groups so as to detect whether an electrical system failure in any one of the electrical fluid pressure control valves or the groups occurs. If occurs, failure control unit is operable to control a corresponding one of the power supply relays so as to cause a corresponding one of the electrical switch valves to selectively connect a corresponding one of the wheel cylinders to a master cylinder.

Abstract: An electrical brake system for a motor vehicle is provided that may include an integrated electrical auxiliary brake. The wheel brakes of the brake system may be actuated via brake application devices. The internal friction can be selectively increased through an electrical auxiliary brake to create a self-locking of the brake application device with an increased brake application force.

Abstract: A vehicle braking system that primarily operates as a pure brake-by-wire system, with optional hydraulic actuation. The system includes a set of four electrically actuated drum brakes. At least two of the wheel brakes include hydraulic actuators that operate to apply the wheel brakes independent of electric control. Each of the wheel brakes is normally operated in response to a control signal generated by the vehicle's brake processor. As such, a primary brake-by-wire system is provided at all four vehicle wheels. The rear brakes are proportioned to the front brakes electrically, according to design criteria.

Abstract: In order to improve an electrically actuatable automotive parking brake with mechanical emergency actuation, the brake pads (52, 54) of the parking brake, which may be either a disk brake or a drum brake, can be applied or released via gear arrangement (100) arranged within or at the brake. The gear arrangement (100) has one power input and one power output, with the power input being coupled with the one end of a flexible shaft, the other end of which being arranged remote from the brake can be coupled with a manual crank, in order to be able to actuate the parking brake mechanically in the case of a failure of the electric actuation.

Abstract: A front/rear interlocking brake system is provided wherein a hydraulic pressure is directly supplied through a lever hydraulic system and a circuit to front brakes. The front brake is provided with a secondary master cylinder for generating a hydraulic pressure due to a brake torque of the front brake. The secondary master cylinder is connected through a lever interlocking hydraulic system and a control valve to a rear brake. A hydraulic pressure is directly supplied from a primary master cylinder through a pedal hydraulic system to the rear brake. Accordingly, the front brakes and the rear brake can be interlockingly operated by operating the lever, and only the rear brake can be operated by operating the pedal.

Abstract: Links are provided for linking a brake caliper pivotally supported through a pin to a vehicle body. A master cylinder is fixed to the vehicle body and is constructed of a first link having one end pivotally supported through a pin to the brake caliper and the other end pivotally supported through a pin to an input member of the master cylinder. A second link is provided having one end pivotally supported through a pin to the vehicle body and the other end pivotally supported through a pin to the first link at an intermediate portion thereof. When the brake caliper is swung in a first direction by a brake reaction force received from a brake disc, the input member is upwardly driven through the first link and the second link, and the master cylinder is operated to generate a secondary brake hydraulic pressure.

Abstract: A motorcycle braking system distributing liquid pressure to a first front brake, a second front brake and a rear brake includes a first master cylinder actuated by a front brake lever and a second master cylinder actuated by a back brake pedal. The first master cylinder is connected directly to the first front brake and the second front brake. The brake system also employs a pressure controller that distributes liquid pressure from the first and second master cylinders to the second front brake according to the liquid pressure from the second master cylinder. A secondary master cylinder supplies a secondary liquid pressure to the rear brake in response to actuation of the first front brake. The secondary liquid pressure supplied to the back brake is transformed by a pressure-transformer. Using these components, the braking system implements a braking control method that provides improved control of the motorcycle while braking.

Abstract: A controller of the invention is used for tractor trailer braking devices having a service brake, an exhaust brake and a retarder brake for a tractor, and a retarder brake for a trailer. The controller includes a main operating switch situated at a driver seat for controlling the exhaust brake and the tractor and trailer retarder brakes, a first interlocking switch for interlocking between the service brake and the tractor and trailer retarder brakes, a second interlocking switch for locking the tractor retarder brake, a first device to detect a condition of an accelerator pedal, a second device to detect a condition of a clutch, a third device to detect a condition of a brake pedal, and a fourth device to detect a condition of a trailer brake. The controller can effectively utilize the exhaust brake, and the tractor and trailer retarder brakes according to the driver's intention.

Abstract: A work brake system applies a reduced air pressure service brake application as a work brake to hold a heavy duty vehicle in place without actuation of conventional spring brakes during frequent start-and-stop operations of the vehicle, such as in refuse collection. The work brake system includes fail safe features to prevent vehicle roll in the event of loss of air pressure, by providing separate primary and secondary sources of pressurized air, and by automatically diverting to application of spring brakes in the event of primary pressure or signal loss.

Abstract: A braking system which employs redundant hydraulic systems. The system has a first hydraulic system coupled to the brake of a first wheel through a first switching valve, and a second hydraulic system coupled to the brake of a second wheel through a second switching valve. Each switching valve will switch the coupled brake to the other hydraulic system, if the pressure within its system falls below a threshold value. For example, if the first hydraulic system fails, the first switching valve switches the first wheel to the second hydraulic system. If the second hydraulic system fails, the second switching valve switches the second wheel to the first hydraulic system.

Abstract: An emergency brake system for wheeled vehicles includes a deformable brake wedge for each tire on one of the vehicle's axles. The brake wedges are constructed and arranged to transfer substantially all braking forces to the vehicle through the vehicle's tires during emergency braking. The system also includes releasable device for allowing the brake wedges to move between inoperative and operative positions and electrically-controlled device for retaining the brake wedges in those positions. While the brake wedges move from the inoperative position to the operative position, a control system temporarily applies the vehicle brakes associated with the tires that engage the brake wedges during emergency braking.

Abstract: A pneumatic brake system for use with an additional brake including a by-pass valve in parallel to a shut-off valve. The by-pass valve is opened only during an actuating or controlling of the pneumatic brake which exceeds a control range and opens up the passage through the brake pressure line irrespective of the switching condition of the shut-off valve. The connection of the brake cylinder line section of the brake pressure line with the atmosphere by the shut-off valve is at least choked when the by-pass valve is opened up.

Abstract: The invention relates to an electro-hydraulic braking system for the wheels of aircraft landing gear. The system comprises two hydraulic pressure sources each feeding a hydraulic circuit that leads to the brakes of two groups of wheels via a single braking control stage. A circuit connects either a solenoid valve electrically controlled by the control unit or else a double metering valve mechanically controlled by the brake pedals via two shuttle valves, to one inlet of each control stage. A second circuit directly connects a solenoid valve to a second inlet of each of said control stages. Each control stage includes two symmetrical internal circuits having one servo-valve per corresponding brake, which servo-valves are cross-connected by means of a respective corresponding controlled valve. In the event of one of the circuits breaking down, the servo-valves associated with the other circuit then serve, after automatic reconfiguration, also to provide braking and anti-skid control in a paired tandem mode.

Abstract: To prevent local abrasion of a lining of a brake pad when one of a plurality of pistons for pressing the lining against a disk plate is rendered operative, a lining 16b mounted on a back plate 16a of a brake pad 16 is separated into two, and a recessed portion 26 or a gap is formed between the two linings 16b in a corresponding relationship to the position of a central one 21 of three pistons 20, 21 and 22. When the central piston 21 is rendered operative, the operating force of the piston 21 is dispersed to the left and right by the recessed portion 26 or the gap to act upon a disk plate 18, and consequently, local abrasion of the lining 16b is prevented.

Abstract: A brake and wheel assembly wherein the available piston stroke for a given envelope can be significantly increased to provide greater brake life between overhauls. The wheel and brake assembly is characterized by a fluid actuated back leg structure which allows a disk pack to be compressed and adjusted not only from its brake head side as is conventional but also from its wheel side. As the brake wears, the back leg structure draws the wheel side of the disk pack toward the brake head while the brake actuator piston or pistons push the disk pack in the wheel direction.

Abstract: Brake wear between braking sites of a vehicle is equalized by measuring work performed at the braking sites, comparing the amount of work performed at each braking site with an average calculated for all braking sites, and increasing braking demand at any braking site performing less than the average amount of work.

Abstract: A braking system for a vehicle. The braking system provides continuous tactile feed back through the brake pedal to the operator of the vehicle that conforms to the degree to which the vehicle brakes are being applied so that the tactile feed-back to the operator conforms to the visual and kinesthetic input received by the operator. The braking system has a brake pedal that is mounted to be depressed in response to a force applied thereto by the vehicle operator. The braking system incorporates both a mechanical brake actuating mechanism and a hydraulic brake actuating mechanism. The braking system provides for selective actuation of the mechanical brake actuating mechanism sequentially in advance of the hydraulic brake actuating mechanism when the brake pedal is depressed. A linkage assembly is incorporated in the mechanical brake actuating mechanism. The linkage assembly provides tactile feed-back to the brake pedal throughout the range of operation of said braking system.

Abstract: A brake control system for a vehicle in which a brake pressure is generated in accordance with a signal from an electronic control unit for applying the brake pressure to vehicle wheels, characterized in that a mechanical brake system is automatically actuated when an unexpected electrical fault has occurred in an electrical brake system.

Abstract: A railroad car brake system, comprising, a pneumatic-to-hydraulic transducer connected to a brake control unit for developing braking pressure in response to a brake command request, and a plurality of disc brake units connected to the pneumatic-to-hydraulic brake pressure transducer and being characterized by the fact that the disc brake units are divided into high speed disc brake units and low speed disc brake units and a control valve is installed between the brake pressure transducer and the disc brake units so that the pressurized fluid may be supplied from the brake pressure transducer either to the high speed disc brake units, or to the low speed disc brake units.

Abstract: A unique addition of hydraulic cylinders, valves, switches and a pump to assist the existing air brake system now used on todays tractor-trailer trucks without altering the basic function of the air brake system and provides independent, boosted intermittent braking without expelling the air.

Abstract: A wheel brake includes at least two brake disks; a brake fluid feed for feeding brake fluid under pressure; and a pressure system connected to the brake fluid feed and acting on the disk brakes. At least one of the brake disks is made of metal, while at least one other of the disks is made of carbon. The pressure system includes actuators respectively associated with the metal disk and with the carbon disk and fed with brake fluid via respective parallel connections; and also a pressure interruption system responsive to the action of the pressure of the brake fluid to take the actuator associated with the metal disk out of communication with the brake fluid feed when the fluid pressure exceeds a predetermined value.

Abstract: In a braking system for a motorcycle, a brake includes a plurality of applicators which are respectively operated by hydraulic braking pressures fed from first and second actuators, and a common antilock modulator is provided for controlling and reducing the hydraulic braking pressures from the first and second actuators. This makes the braking system having antilock control function simplified in structure.

Abstract: A vehicle disc brake is provided which, in a preferred embodiment, includes a first caliper pivotally mounted with respect to the vehicle, a first brake shoe slidably mounted with respect to the first caliper for selective contact with a vehicle wheel rotor, an electric actuator to selectively move the first shoe into engagement with the rotor, an actuator plate mounted for relative motion with respect to the vehicle and operatively associated with the first caliper wherein movement of the first caliper resultant of the first shoe engagement with the rotor causes the actuator plate to move, a second caliper generally locationally fixed with respect to the vehicle wheel axis, a second brake shoe mounted by the second caliper operatively associated with the actuator plate for engagement with the rotor, and a ball captured in a ramp between the actuator plate and second brake shoe for converting movement of the actuator plate into movement of the second brake shoe to engage with the rotor.

Abstract: A power-assisted hand brake for motor vehicles, which can be operated in an automatic and power-assisted mode with the aid of an electric motor. If the power assisted brake fails, a conventional parking brake is operated mechanically to apply emergency brakes. The handbrake includes a rotatable spindle with a threaded nut thereon which operates the brake by use of the motor. A carrier plate and pivot plates function to disconnect the nut so that a hand-operated lever can be used to manually operate the brake.

Abstract: A double caliper braking system of differential action, operated by a pressure circuit with two parallel branches connected to the calipers. One of the brake calipers is of smaller dimensions than the other. One of the two branches is provided with a pressure regulator device to cause only one of the two calipers present in the system to act up to a certain threshold value.

Abstract: A brake control system which provides both adaptive braking operation and traction control operation includes a brake lining temperature prediction mechanism which enables the control system either to permit traction control operation or to disable traction control operation so that the brake linings will not be worn out prematurely by traction control operation when the linings are above a temperature threshold.

Abstract: An electric brake system for a motor vehicle has a plurality of braking force generating mechanisms associated with respective road wheels and including electronic actuators mechanically separate from a brake pedal. In the event of a failure of at least one of the braking force generating mechanisms, the electric brake system selects and operates normal braking force generating mechanism or mechanisms for braking the motor vehicle stably with boosted braking forces. The braking force generating mechanisms are mechanically separate from the brake pedal and operable independently of each other. Failure detecting circuits are associated respectively with the braking force generating mechanisms, for detecting a failure of the braking force generating mechanisms and producing a failure signal representing the failure. The electric brake system includes a controller for controlling the braking force generating mechanisms in response to the signal from the brake pedal.

Abstract: A servo-assisted device for operating a parking brake of a moto vehicle is described, consisting of a control lever for a brake cable or rod, mounted rotatably on a pivot, a ratchet mechanism adapted to permit rotation of the lever in a predetermined direction and a push button for disengaging the ratchet mechanism; the principal characteristic of the invention consists in the fact that the brake cable or rod is connected to the control lever through an actuator pivoted beneath the control lever and to a movable element of which the said brake cable is fixed.

Abstract: A drum brake has two sets of braking linings. The drum brake includes a brake plate and a brake drum. An additional cylinder is mounted on an outer periphery of the brake plate. The additional cylinder is actuated by hydraulic oil on depression of an additional brake pedal provided proximate to a clutch pedal of the car. A further brake lining is provided around an outer periphery of the brake drum. On depression of the additional brake pedal, the brake lining engages with the outer surface of the brake drum to provide additional stopping capability.

Abstract: The actuator (10) of a brake, such as a disc brake, is controlled by an electric motor (34) which drives a pump (38, 50, 62) ensuring that the pressure of the brake fluid in a control chamber (44) rises. A crankshaft (38) driven by the electric motor (34) imparts a to-and-fro movement to a plunger piston (50) in a pumping chamber (62). This chamber (62) communicates with a brake-fluid reservoir via an intake duct (74) controlled by way of a valve (76, 78) and with the chamber (44) via a delivery duct controlled by way of a valve (58, 60). Furthermore, the control chamber (44) communicates with the reservoir via a recycling duct (80) controlled by way of a solenoid valve (82). The entire hydraulic circuit so formed is accommodated in the body (12) of the actuator.

Abstract: The invention is directed to a system for increasing and/or extending the operation service life of an aircraft brake disk stack by selectively limiting the number of brake assemblies which comprise the aircraft landing gear configuration and which are put into operation during the time the aircraft is on the ground and subject to low speed taxi braking cycles while also providing that all of the brake assemblies of the total available on the aircraft are operational during other portions of the landing and takeoff cycle of the aircraft.

Abstract: A braking system for an aircraft towing vehicle which supports the nose wheel of an aircraft in a raised position and firmly clamps it to the vehicle. The braking force generated by the front wheels of the towing vehicle is greater by about 2:1 to 8:1 than the braking force at the rear wheels. The braking system has two hydraulic circuits employing identical braking cylinders at all four wheels of the vehicle. The number of cylinders per wheel are varied and different effective lever arms are used to generate like braking forces at each side of the vehicle, and the relatively greater braking force at the front wheels, even if one of the hydraulic circuits fails. The system limits the braking force at the front and rear wheels to maximum values to prevent excessive forces from damaging the nose gear of relatively smaller aircraft.

Abstract: Braking unit for vehicle, of the type comprising an axial actuating helical spring maintained in release position, against its elastic reaction force, through a screw-nut system rotatively driven by an electric motor, the spring acting upon the brake through the intermediary of a hydraulic master cylinder of which the piston is axially connected to an abutment ring of the spring also mechanically connected, via a screw-nut system to the rotor of an electric motor, such an unit being applied to a spring braking system for a vehicle possibly with a built-in park brake.

Abstract: A braking system for an automotive vehicle, having a first brake system and a second brake system. The first brake system includes a master cylinder responsive to an operation of an operator-controller brake operating member, for generating a fluid pressure which corresponds to an operation value of the brake operating member, and a first brake actuated by the fluid pressure generated by the master cylinder. The first brake is adapted to produce a braking effect which is smaller than a desired or optimum braking effect corresponding to the operation value of the brake operating member. The second brake system has a second brake and is controlled by a controller such that the second brake produces a braking effect which is equal to a difference between an actual braking effect applied to the vehicle, and the desired braking effect.

Abstract: A manually/electrically operated brake system for applying a brake to a wheel of a vehicle, including a master cylinder operated by a brake operating member, to generate a manually controlled braking pressure according to an operation of the brake operating member, a wheel brake cylinder for applying a brake to the wheel, a primary fluid passage for connecting the master cylinder to the wheel brake cylinder, an electrically controlled pressure generating device for generating an electrically controlled braking pressure to produce a required braking effect determined based on at least one of an operating force and an operating stroke of the brake operating member, and a switching device provided in the primary fluid passage, for applying the electrically controlled braking pressure to the wheel brake cylinder while disconnecting the master cylinder from the wheel brake cylinder when the electrically controlled pressure generating device is normally functioning, and for applying the manually controlled braking

Abstract: The actuating device of a braking mechanism comprises an electric driving motor and a gear pinion meshing with a first gear wheel integral with a screw screwed into a nut pressing on a plunger for application of the brake. The nut 13 carries a second gear wheel 22 having number of teeth which differs very slightly from that of the first gear wheel 31, for example by one tooth, to make a drive system with this first wheel in differential translation of the nut 13. Application to an electrically controlled and quick release brake.

Abstract: A tandem parking brake caliper system for use with the rotor of a disc brake of a wheel of an automotive vehicle. The system includes a caliper adapted to be slidably mounted in a boss of an anchor extension mounted to a non-rotating portion of the vehicle. The caliper surrounds a radially outer peripheral portion of the rotor on opposite sides thereof. Frictional brake linings are mounted on the caliper surfaces which face the rotor. A movable piston is mounted in a bore of the caliper for engaging one of the linings for forcing the linings into engagement with the rotor upon the application of force onto the piston and the resulting translation of the caliper. An actuating lever is rotatably mounted to the assembly and includes a cam surface for engaging and applying translating force to a cam follower surface of the piston. The lever is connected to a cable actuating the lever.

Abstract: A hydraulically controlled disk brake of a motor vehicle having at least one hydraulically actuable brake piston that is arranged in a caliper and is guided in at least one cylinder. The brake has a duct which continuously serially connects the cylinders in each half of the caliper, this duct having separate inlet and outlet openings. A check valve for each inlet and outlet opening is respectively arranged in front of the first cylinder after the inlet opening and behind the last cylinder before the outlet opening with respect to flow direction.

Abstract: A brake system for a motor vehicle having three sources of communicating pressurized fluid to wheel brakes and having a mechanical brake. Two of the sources of communicating pressurized fluid are the reservoirs of a dual master cylinder and provide first and second hydraulic brake subsystems. The remaining source is an emergency master cylinder and provides a third hydraulic brake subsystem. The mechanical brake and the third hydraulic brake subsystem are operatively connected to an emergency brake pedal. Disc brakes each have a pair of floating calipers, each caliper being in fluid communication with a pair of sources of communicating pressurized fluid. Drum brakes have at least one dual chambered wheel cylinder in fluid communication with two sources of communicating pressurized fluid. The first and second hydraulic brake systems, as well as the emergency brake pedal, operate brakes on each of the four wheels of a motor vehicle.

Abstract: An anti-skid braking system for an automotive vehicle, including a first brake system and a second brake system. The first brake system has a master cylinder for generating a fluid pressure corresponding to an operation value of a brake operating member, a first brake for a wheel of the vehicle equipped with a brake cylinder actuated by the pressure of the master cylinder, and a first solenoid valve device between the master and brake cylinders and operable between a first and a second position for communication of the brake cylinder with the master cylinder and a reservoir, respectively. The braking system includes a second brake system which has a second brake cooperating with the first brake to apply a brake to the wheel; a speed sensor for detecting a speed of the wheel; and an anti-skid controller for estimating a slip ratio of the wheel based on the detected speed.

Abstract: A brake system actuator which is actuated to increase pressure delivered to a wheel brake through a drive transfer mechanism powered by a variable torque electric motor, the actuator piston being retracted by a substantially constant torque spiral spring which is preloaded to drive transfer means in the opposite direction when the motor is deenergized. This is particularly useful in a brake actuator which is a component of a vehicle wheel brake and wheel anti-lock control system.

Abstract: An anti-squeal braking system for an automotive vehicle, including a first brake having a brake rotor, a friction member disposed opposite to the brake rotor, and a hydraulically operated actuator for forcing the friction member against the brake rotor, and further including a second brake cooperating with the first brake to apply a brake to the vehicle. The first and second brakes are controlled by an anti-squeal controller such that the first brake is operated without a braking squeal, while the second brake is operated so as to provide a braking effect equal to a difference between an actual braking effect applied to the vehicle by the first brake, and a desired braking effect that should be applied to the vehicle. The desired braking effect is predetermined corresponding to an operation value of an operator-controlled brake operating member sensed by a detector device.

Abstract: An improved friction brake system for a transit vehicle is disclosed. The conventional friction brake system for a transit vehicle utilizes an integral service brake and emergency-parking brake actuator. The service brake portion is air powered while the emergency-parking brake portion is spring powered. It has been conventional to apply full service air brake and emergency spring brake during emergency stops. An accelerometer switch is typically connected in circuit with the service brake portion to prevent the service brake from turning on if their is sufficient deceleration. The accelerometer switch often does not react quickly enough to prevent the onset of the service brakes. The present invention utilizes a time delay switch to delay the onset of service brakes until after the spring-activated emergency brakes react.

Abstract: A braking system employing an antilock device which has two brake actuating mechanisms responsive to input hydraulic pressure through the antilock device. Valves are provided in the control mechanism for a second brake actuating mechanism which provide hydraulic cylinders for controlling the brake mechanism. The hydraulic cylinder of such a valve is vented until the controlling hydraulic system reaches a minimum pressure level. This pressure level is determined to be above that of the residual pressure level of the antilock mechanism. In a first embodiment, direct hydraulic control is provided to the multiple brake actuating mechanisms. In the second preferred embodiment, the reaction force to braking of the first brake actuating mechanism controls the brake pressure through a second master cylinder to the second brake actuating mechanism.