Abstract: An anti lock braking system for commercial vehicles is described. The system includes a rear axle brake assembly having a rear brake for each rear wheel, a relay valve for controlling rear axle brakes and a plurality of pressure modulator valves operatively connected to the relay valve, each having an outlet connected to one of the rear brakes. Multiple connector cartridges are used to sealingly connect the relay valve to each of the pressure modulator valves. The connector cartridges have a first end defining a non rotation-dependent fitting, such as a cartridge fitting, cooperating with a corresponding port cavity to form the sealed connection.

Abstract: A method and apparatus for monitoring the operation of vehicle brakes on a vehicle equipped with an electronic braking system as is commonly used to provide traction control (TC) and/or an anti-lock braking system (ABS). The speed at which a first wheel located on a first side of a vehicle rotates in relation to the speed at which a second wheel located on a second side of the vehicle rotates during particular braking events is examined. For each wheel, any difference or "error" in the rotation speed during the select braking events relative to the other side wheel is accumulated or integrated over a select duration until a threshold difference value is reached which indicates a malfunction at the subject wheel end. The accumulated difference is periodically adjusted to account for normal or acceptable levels of wheel speed variation.

Abstract: An air supply system for a motor vehicle air brake system incorporating a desiccant type air dryer. The purge capacity of the air dryer is enhanced providing greater water and contaminant removable characteristics for the air dryer. The system incorporates a pressure reducing element and a control system for the system compressor causing air passing through the air dryer to be at a higher pressure than that necessary for charging the system reservoir. The higher pressure air supplied to the air dryer provides greater volumetric capacity for the purge volume of the air dryer. In this way an air dryer purge volume of a given size provides a greater purge capacity.

Abstract: A compressed air system includes an air drying subsystem which can be configured either in an intermittent mode, in which a separate purge volume intermittently purges the desiccant used by the air drying systems when the compressor goes off load, or in a continuous flow mode, in which the purge volume is replaced by a second desiccant cartridge and the two desiccant cartridges are alternatively purged and used to dry the compressed air.

Abstract: A compressed air system includes an air dryer which includes a desiccant for drying compressed air passed through the desiccant before the compressed air is received in a storage reservoir. A humidity sensor is installed in the system downstream of the desiccant for measuring the relatively humidity of the air after it passes through the air dryer. A control module is programmed such that if the humidity level increases above 80%, a timer is started. If a time period of several hours elapses without the humidity level decreasing below 50%, a depleted desiccant and/or a system malfunction is indicated, and an appropriate warning device is actuated.

Abstract: A compressed air system for an automotive vehicle includes an air compressor which generates compressed air which is dried by an air dryer and stored in an air storage reservoir. The air dryer is regenerated by using compressed air stored in the storage reservoir instead of compressed air stored in a purge volume within the air dryer. A timer actuated solenoid operated valve controls the length of the purge cycle.