Bendix Commercial Vehicle Systems M-40HF PMV SD - Manual

1
Supply Port
(Casting has
“1, SUP”)
Exhaust Port
(Body has
“3, EXH”)
Supply
Port
(Casting has
“1, SUP”)
Exhaust Port
(Body has “3, EXH”)
Electrical
Connector
Mounting Holes
(.33" Diameter
Through Body)
Alternate Push-to-
Connect Version,
Showing Optional
Packard Connector
Electrical
Connector
Delivery Port
(Casting has
“2, DEL”)
Bendix ® M-40HF ™
Modulator
Bendix ® M-40QR ™
Modulator
SD
-13
-4
95
8
DESCRIPTION
The Bendix ® M-40QR ™ (quick release) and M-40HF ™ (high
flow) pressure modulator valves (PMVs) are high-capacity,
on/off air valves that incorporate a pair of electrical
solenoids for control. See Figure 1. The solenoids provide
the electro-pneumatic interface between the vehicle’s
electronic control system and the air brake system. For
example, the PMV is used to control the braking function
of service actuators during antilock activity.
The modulator consists of a die cast metal and plastic body
that houses one normally-open solenoid, one normally-
closed solenoid, and an inlet and exhaust diaphragm
valve. A three-pin weather-resistant electrical connector
is an integral part of the modulator solenoid assembly
and delivers the vehicle controller’s commands to the
modulator. Two mounting holes are provided for frame or
crossmember mounting of the valve.
The Bendix M-40QR modulator is the direct replacement
for the Bendix M-32QR modulator (See Figure 2). The
Bendix M-40QR modulator has a bias valve to provide an
internal quick-release function.
Bendix ® M-40QR ™ and M-40HF ™ Pressure Modulator Valves
FIGURE 1 - M-40QR ™ AND M-40HF ™ PRESSURE MODULATOR VALVES
The supply, delivery and exhaust ports on the Bendix M-40
modulators have embossed identification codes.
Port ID
Air Hose
Connection
Function
1, SUP Supply
Air enters from a valve (typically
foot, relay or quick release).
2, DEL Delivery
Air is delivered to the service
actuators.
3, EXH Exhaust Air is vented to the atmosphere.
FIGURE 3 - PORT DESIGNATION AND FUNCTION
APPLICATIONS
Bendix M-40 modulators may be used for various purposes
on a vehicle including ABS and stability interventions. In
applications using these PMVs, an external quick release
valve may also be required, depending on the system
design. Where the modulator is used for individual wheel
control applications, it is typically the last control valve
through which air passes on its way to the service brake
actuator. See Figure 4 for a typical system schematic.
Previous Model
M-32 ™ Modulators
Bendix M-32QR ™ (left) and M-32 ™
(right) Modulators
FIGURE 2 - M-32 ™ MODULATORS