235
ABS operation and maintenance.
Upon switching ON the starter and instru-
ments, the ABS performs continuous diagnostics of troubles and informs the driver
of its results. Pilot lamp 2 (Fig. 141) goes ON, when switching on the instruments,
and goes OFF after checking ABS serviceability if no faults have been discovered.
Fig. 141. ABS Control Unit:
1 – ABS actuating key when moving in “OFF-ROAD” mode; 2 – pilot lamp
ABS functioning check-up:
1. Make sure that the switching devices (cables, plug-and-socket joints) of
the electronic control unit, modulators and senders are connected securely by ex-
ternal examination.
2. Turn on the storage battery button on the instrument board. Set the starter &
instrument switch to the
ПРИБОРЫ
(“instruments”) position. In so doing a pilot
lamp goes ON. If the electric equipment is in good working order, the pilot lamp
should go OFF in 2-3 s.
3. Start the engine and bring the pressure in the circuits to the norm 650-800 kPa
(6.5-8.0 kg/cm
2
). Begin movement. If the travelling speed exceeds 7 km/h the pilot
lamp goes OFF. If the pilot valve does not go ON, check the installation of the
senders in the wheel units, perform the control check of the system.
4. Accelerate the truck to the speed of 35–45 km/h and then brake it sharply.
In so doing the wheels should not be blocked.
The pilot lamp should go ON and then OFF when turning on the storage bat-
tery button and starter & instruments switch again to the position “Instruments”.
If any failure occurs, the ABS is completely or partially switched OFF and the
pilot lamp on the dashboard goes ON. The failure code is stored in the control unit
memory for a long time and may be asked when repairing.
The system does not require special maintenance, except control over func-
tioning and check the installation of the ABS senders when adjusting or replacing
bearings in the wheel units or replacing the brake linings (if the hubs have been
removed). For proper ABS operation the clearance between the stator and the rotor
should not exceed 1.3 mm. To set a minimum operating clearance between the sta-
tor and the rotor, hang out the wheel and then the sender body, applying a force of
120-140 N (12-14 kgf) onto its end, move it in the clamping bush in the axial di-
rection up to the stop at the rotor crown and turn over the wheel hub through 2-3
turns. If the sender movement in the bushing is hindered by penetrated mud, rust,
disassemble the unit and apply a thin layer of
УСсА
GOST 3333-80 graphite
grease or
ВНИИ
НП
-225 GOST 19782-74 paste onto the inner surface of the
bushing.
The faults diagnostics for ABS, D version, made by WABCO is performed with
the help of the Wabco 4463003200 diagnostic controller. The diagnostic controller is