The BMPM braking system, one of the hydraulic systems, is a torque-lock system designed to meet the Society of
Automotive Engineers (SAE) J2118 specifications for braking performance on BMPM-type equipment. It has a
braking capacity of 3.2 times the machine mass and contains a service brake, a secondary brake, and a parking
brake with gear interlock.
The service brake is a function of the joystick control lever. When propulsion (forward or reverse) is required, the
hydraulic system releases the gear drive to allow components to rotate. Returning the joystick to the neutral
position will stop all motion within the torque hubs.
The secondary brake is derived from the mechanical locking of the gear components within the torque hubs.
Hydraulic pressure must be relieved in order to release the mechanical locks and allow internal motion.
The failsafe parking brake is set by engaging the EMERGENCY STOP switch on either operator platform control
pedestal. This action releases hydraulic pressure from the drive system, allowing mechanical locking of the gear
components within the torque hubs, and shuts off the engine. This same mechanical locking is also set to occur in
the event of engine and/or electrical power loss.
Screed Bolt-On Extensions
Figure 8. Bolt-On Screed Extension.
The BMPM is equipped with two bolt-on screed extensions (Figure 8, Item 1) that can be attached to each side of
the screed, extending paving width to a total of 20 ft (6.1 m). Each extension contains heaters that are identical to
those on the main screed, allowing for heating across the entire 20-ft (6.1-m) paving span.