Belarus 1025/1025.2/1025.3
Section I. Possible malfunctions
I17
Malfunction, symptom
Correction method
Pressure controller is often actuated (switches compressor on) without air intake
from the receiver
Air leakage from pneumatic system or
Find out and eliminate air leakage
pressure controller, or damage of the
controller check valve
Controller operates in the safety valve mode
Adjusting cover is screwed up to great value Adjust controller
Jamming of discharge piston of the
Disassembly pressure controller and
diaphragm unit
eliminate jamming
No clearance between relief valve and
Unscrew cover, clean outlet openings and
lower cover, cover outlet openings are
check for clearance
clogged
No air supply to connecting hose via air bleed off valve
Rod of air bleed off valve in the pressure
Screw up connecting hose nut to the
controller is not sunk enough.
coupling to the full.
Pressure controller has switched
Reduce cylinder pressure to below 0.65
compressor over to idle run
Mpa (6.5 kgf/cm
2
)
Displacement of rubber ring on the
Unscrew the cover, check position and
air bleed off valve
state of rubber ring
Trailer brakes are inefficient
Brake valve doesn’t provide in the
Make adjustment of brake valve and its
control main pipeline pressure
drive (see Section H “Adjustments”)
0.77…0.80 Mpa (7.7…8.0 kgf/cm
2
) or
0.53…0.6 Mpa (5.3…6.0 kgf/cm
2
) for
Hungary and Germany.
Brake valve doesn’t provide pressure
Make adjustment of brake valve and its
drop in the connecting pipe-line to zero
drive (see Section H “Adjustments”)
Pressure in the connecting pipe-line
Check state of connecting main pipe-line;
slowly drops to zero
atmospheric valve opening, brake pedal
travel.
Trailer brakes are released slowly
Disturbed adjustment of brake valve
Make adjustment (see Section H ““Adjustments”)
and its drive
Disturbed operation of trailer braking system Adjust it
