Modulator Valve Operation Modes - BENDIX GEN 4 GEN 5 ABS Manual

Inlet
Exhaust
FIGURE 10 - Normal Apply and ABS/ATC Apply
Inlet
Exhaust
FIGURE 12 - ABS/ATC Hold

Modulator Valve Operation Modes

1. Apply–Air flows straight through valve. Hold diaphragm
is vented to allow air flow. Inlet pressure feeds behind
release diaphragm to block the exhaust port. No
solenoids are activated.
2. Normal Release–With quick release function, hold
diaphragm is vented and there is no pressure at the
inlet port. Air is allowed to flow from outlet to inlet. Since
release diaphragm is not pressurized, air also flows out
the exhaust port. No solenoids are activated.
10
Vents
Solenoid
Hold
Diaphragm
Outlet
Release
Diaphragm
Outlet
Inlet
Zero
Pressure
Exhaust
FIGURE 11 - Normal Release
Inlet
Exhaust
FIGURE 13 - ABS/ATC Release
3. ABS/ATC Hold–The hold solenoid is activated. Both
diaphragms are pressurized. No air flows through the
valve.
4. ABS/ATC Release–Both solenoids are activated. The
hold diaphragm is pressurized, blocking the inlet air.
The release diaphragm is vented, allowing air to flow
from the outlet port back through the exhaust port.
Outlet
Outlet