BENDIX ATR-1 ANTILOCK TRACTION RELAY, Manual

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2
ATR-1
™
ANTILOCK
TRACTION RELAY
VALVE
CONTROLLER
FIGURE 2 - ANTILOCK TRACTION ASSEMBLY
TRACTION CONTROL
SOLENOID
SUPPLY
SERVICE
DOUBLE
CHECK VALVE
DELIVERY
EXHAUST
RELAY PISTON
INLET-EXHAUST
VALVE
BLEND BACK
PISTON
SOLENOID
CONNECTOR
FIGURE 3 - ATR-1 ™ ANTILOCK TRACTION ASSEMBLY
antilock components and their operation. For a description
of antilock operation, refer to the appropriate Service Data
Sheet covering the electronic controller used with the
ATR-1
™
valve.
SERVICE BRAKES APPLYING (FIGURE 4)
Reservoir air pressure is present at the supply port and flows
through internal body and cover passages to the supply of
the normally closed (NC) traction control solenoid.
Brake application air enters the ATR-1
™
valve’s service port
and is conducted to the single check valve. The check valve
diaphragm flexes in response to application pressure and
seals the passage to the open exhaust of the traction
solenoid. Air flows through the service piston then through
the center of the blend back and through a passage in the
cover to the top of the service relay piston. In response to air
pressure, the relay piston moves into contact with the
exhaust portion of its inlet and exhaust valve. With the
exhaust passage sealed, continued movement of the piston
unseats the inlet portion of the inlet and exhaust valve,
allowing supply air from the reservoir to flow out the ATR-1
™
valve’s delivery ports to the brake chambers.
OPERATION
GENERAL
Because the ATR-1 ™ is essentially a relay valve, the following
description of operation refers to its function in the vehicles
air brake system and does not address all of the separate