Tractors are equipped with left- and right-hand service brakes actuated by means of the pedals (5, 6) parking brake with an independent mechanical manual control by means of the handle (7) acting upon the service brakes.
The service brake actuator is a hydro-static one to be operated by the left-hand (3) and right- hand (4) master hydraulic brake cylinders and the left-hand (12) and right-hand (8) service cylinders.
The independent manual mechanical control of the brakes is exercised by means of the handle (7) through a link-age and leverage system.
1, 2 – pipeline; 3, 4 – left- and right-hand master cylinder; 5, 6 – right- and left-hand brake pedal; 7 – parking brake handle; 8 – service brake of the right-hand brake; 9 – lever of the right-hand brake; 10 – carriage; 11 – lever of the left-hand brake; 12 – working cylinder of the left-hand brake; 13, 14 – connecting hose.
Wet Service Brakes
The service brakes are of 8-disk type. The friction disks (2) are installed in splined ends of the hub drive pinions (16). The pressure disks (6) are similar in design to those used in dry brakes, but with a reduced angle of gradient of pits for balls, to ensure the required force of compression of the packs of the friction and intermediate disks.
The intermediate disks (3) are fixed from turning in their cases (1, 13) by means of shoulders made over the outer profile. The leak proofness of the oil baths is ensured by the O-rings (15, 24), gaskets (10, 14) and rubber boots (5, 23). The cases are provided with inspection (22) and drain (12) plugs.
Parking Brake. The service brakes having a separate actuator from the control lever.
Wet Clutch for Locking Up the Differential
The lock-up clutch (17) comprises six disks with brake ceramic-metal linings fitted on the splined boss (18) connected with the hub drive pinion (16). A pack of six friction and five intermediate disks is compressed as oil under pressure is fed to the diaphragm space. The frictional torque developed thereby ensures interlocking of the rear axle differential. The clutch is made in a single case with the service brake. It shares a common oil bath with the brake and is sealed by means of the cover (20) and special corrugated boot (23) slipped over the adaptor (21) which delivers oil to the working space of the diaphragm.
Wet Brake Control
The service brakes control actuator is of hydrostatic type.
The parking brake control is mechanical.
Wet brake adjustment: pedal travel 100…120 mm under the force of (300±30) N applied to one pedal. It is adjusted by the bolts (25).
The oil level in the brake casings shall reach the edges of the holes of the inspection plugs (22) on the front walls of the casings. The oil in the brake casings shall be changed simultaneously with changing of oil in the transmission.
The mark of oil to be used for the brakes is similar to that of oil in the transmission. The draining plugs (12) located at the bottom are provided for draining oil from the brake casings. The oil level in the casings shall be checked after every 500 hours of operation of the tractor.