952.5-0000010 OM
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4.7 Trailer brake actuator
4.7.1 General information
Your tractor can be equipped with a double-line pneumatic actuator for trailer brakes or
a hydraulic actuator for trailer brakes. Brief data on the structure of the double-line pneumatic
actuator for trailer brakes is given in subsection 4.7.2. Brief data on the structure of the hy-
draulic actuator for trailer brakes is given in subsection 4.7.3.
ATTENTION: ALL ADJUSTMENT OPERATIONS OF THE BRAKING SYSTEM AND
THE ACTUATOR OF TRAILER BRAKES AS WELL AS FAULTS ELIMINATION SHALL BE
CARRIED OUT WITH THE ENGINE KILLED AND THE TRACTOR STAYING IN A HORI-
ZONTAL POSITION, WHICH SHALL BE SECURED BY STOP BLOCKS PUT BEHIND THE
WHEELS AND PREVENTING THE TRACTOR FROM SELF-MOVEMENT!
4.7.2 Double-line pneumatic drive of trailer brakes
Tractors BELARUS-952.5 in base-line configuration are equipped with double line
pneumatic drive providing brake control of trailers and agricultural machines, equipped
with two-line pneumatic brake drive. The pneumatic drive is used also for tires charging
and other purposes where energy of compressed air is required. The configuration of two-
line pneumatic drive is shown in figure 4.7.1.
In the pneumatic drive are installed the connecting heads 11, 12 (figure 4.7.1) of
valve type. The valves of connecting heads prevent air outlet, if pneumatic drive is used
without trailer (for example, tire charging) and at emergency trailer disconnection. At con-
nection of the trailer brake lines with tractor lines the valves of connecting heads open,
providing passage of the compressed air from tractor pneumatic drive to the trailer. It is
necessary to connect pneumatic lines, if there is no pressure in tank 4 of the tractor.
ATTENTION: BEFORE CONNECT OR DISCONNECT TRACTOR AND TRAILER
PNEUMATIC LINES, ENGAGE PARKING BRAKE! IT IS NECESSARY TO CONNECT
TRACTOR AND TRAILER PNEUMATIC LINES WHEN THERE IS NO PRESSURE IN
PNEUMATIC SYSTEM OF THE TRACTOR!
1 – compressor; 2 – pressure regulator; 3 – air bleed valve; 4 – tank; 5 – air pressure
indicator; 6 – alarm lamp of emergency air pressure; 7 – air pressure sensor; 8 – emergency
air pressure sensor; 9 –condensate drain valve; 10 – feed line; 11 – connecting head of feed
line (with red cap); 12 – connecting head of control line (with yellow cap); 13 –control line;
14 – brake valve.
Figure 4.7.1 –
Configuration of double-line pneumatic drive of trailer brakes
