New Holland WorkMaster 50 Service Manual page 370

Brakes and controls - Mechanical service brakes
Mechanical service brakes - Overview
See Mechanical service brakes - Exploded view (33.120).
Oil immersed brakes used, has two brake discs (1) both externally lined with friction material are supported by brake
actuator (2) mounted on brake housing (8). An actuating assembly is mounted between the brake discs (1), which
consists of two discs (3) separated by steel balls (4) but connected by short springs (5). Lugs on the discs are attached
to a yoke (6) on the operating rod.
When the tractors moving, the brake discs rotate with the axle shaft. If brake pedal is depressed, its associated
brake links cause this actuating discs to turn in opposite directions. As the pressure plates turn, the balls (4) clamped
between the actuating discs roll over the inclined surfaces of their sockets (7). In the plates, thus causing the actuating
discs to move axially outwards to contact the rotating brake discs which in turn contact the inner faces of the brake
housing (8) and differential support and back-up discs. This movement increases the axial force on the housing,
support back-up disc and actuator and produce brake torque. This action causes the axle shaft, hence the associated
driving wheel of the tractor, to slow down and then stop rotating completely. On release of the brake, retracting springs
(5) return the plates to their original positions.
The force exerted by the driver is transmitted to the brake assembly by a system of levers and rods. The actuating
system not only connects the pedal with the brake but also increases the relatively small force available at the pedal
to the much larger force required to brake the vehicle. It can also permit the braking effort to be divided between the
axles in the required proportion.
Left wheel brake pedal can be retained in the applied position by means of latch controlled by a hand lever fitted at
right hand side, below operator's seat used as a parking brake.
47866583_ 02/12/2015
33.1 [33.120] / 7