7
Figure 9 - Bendix M-40QR & M-40HF Modulators DIN Symbol
MODULATOR REMOVAL
1. Locate the modulator that will be replaced and clean
the exterior.
2. Identify and mark or label all air hoses and their
respective connections on the valve to facilitate ease
of installation.
3. Disconnect both air lines and the electrical connector.
4. Remove the modulator from the vehicle.
5. Remove any air hose fittings present.
These fittings
will be re-used in the replacement modulator.
MODULATOR INSTALLATION
1. Install all previously-removed air hose fittings, making
certain thread-sealing material does not enter the
valve.
2. Install the assembled valve on the vehicle.
3. Reconnect both air lines to the valve using the
identification marks made during step 5 of
Modulator
Removal
.
4. Reconnect the electrical harness to the modulator.
5. After installing the valve, test all air fittings for excessive
leakage and tighten as needed.
TECHNICAL INFORMATION
Mode
Modulator Type
Port
Options
Supply Port (from brake, relay, or
quick release valve): 1/2" NPT
Delivery Port (brake actuator):
• 1/2" NPT
• Push-to-connect for 1/2" tubing
Solenoid
Voltage
12 Volts DC Nominal, optional 24 Volt
available
Weight
1.35 pounds
Maximum
Operating
Pressure
150 psi gauge
Operating
Temperature
Range
-40°F (40°C) to 185°F.
[A short-term operating temperature
of 230°F (110°C) for up to 10% of the
valve’s lifetime is acceptable.]
Pressure
Differential
1 psi maximum (supply to delivery)
Mounting
Hole Sizes
0.33" diameter through body
Figure 8 - Bendix
®
M-40QR
™
& M-40HF
™
Modulators
Packard
Terminal
Name
Bayonet
Terminal
Name
Function
41
2
Source
42
3
Hold
43
1
Exhaust
Valve
Port
Function
1
Supply
2
Delivery
3
Exhaust
Bendix
®
M-40HF
™
Modulator
Bendix
®
M-40QR
™
Modulator
