BENDIX SD-03-904 Manuel D’Utilisation

1

The Bendix

®

 QR-1C

®

 is a dual function valve. The valve’s 

primary function is to serve the emergency side of a spring 
brake actuator as a quick release valve. In addition, it 
functions as an anti-compound device. The double check 
valve prevents a service and emergency brake application 
from occurring simultaneously.
The QR-1C

®

 valve is generally mounted on the axle and 

serves two spring brake actuators. The air connections to 
the QR-1C

®

 valve are as follows:

1. QR-1C

®

 valve delivery port (2) connected to emergency 

port of spring brake.

2. QR-1C

®

 valve balance port (1) connected to delivery 

of brake valve or relay valve. NOTE: If relay valve 
is installed on vehicle, it should be connected to the 
delivery side (not service or signal side).

3. QR-1C

®

 valve supply port (1) connected to delivery of 

park control valve.

In its standard confi guration the valve is designed to deliver 
within 1 psi of control pressure. However, for special 
applications the valve is available with greater differential 
pressure or zero hysteresis. QR-1C

®

 valves also come 

with optional noise reducing foam crosses or silencers. 
Some QR-1C

®

 valves can also come with biased double 

check valves. These double check valves contain a beaded 
seat cap nut (Figure B). The bias design minimizes low 
differential leakage.

Mounting Holes

Delivery (2)

Supply
Port(1)

Body

Quick Release

Diaphragm

Delivery

Sealing Ring

Exhaust

Cover

Sealing 

Ring

Double Check

Diaphragm

Balance Port(1)

Cap Nut

Beaded

(Biased) Seat

Non-Beaded

Identifi cation

Mark