User's Manual

5
TRACTION CONTROL - SERVICE APPLICATION
GENERAL
While under the control of an antilock traction controller,
the ATR-2
™
valve’s solenoid is able to initiate a brake
application that allows the traction system to control wheel
spin upon acceleration under 25 mph. When wheel spin is
detected and the vehicle is stopped, or moving at any speed
up to 25 mph, the antilock traction controller instantly
energizes the solenoid in the ATR-2
™
valve which then
applies air to each of the rear axle modulators as shown in
Figure 12. The modulators are equipped with solenoid valves
FIGURE 7 - BOBTAIL TRAILER SERVICE BRAKES APPLYING (LESS THAN 80 PSI)
CONTROLLER
BRAKE
VALVE
CHECK VALVE
RELAY PISTON
INLET EXHAUST
REAR AXLE
RESERVOIR
TRAILER SUPPLY
PROPORTIONING
PISTON
TRACTION
SOLENOID
INLET EXHAUST
MODULATOR
SERVICE BRAKE
FIGURE 8 - BOBTAIL TRAILER SERVICE BRAKES HOLDING
CONTROLLER
BRAKE
VALVE
CHECK VALVE
RELAY PISTON
INLET EXHAUST
REAR AXLE
RESERVOIR
TRAILER SUPPLY
PROPORTIONING
PISTON
TRACTION
SOLENOID
INLET EXHAUST
SERVICE BRAKE
MODULATOR