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More info: visit www.bendix.com 1-800-AIR-BRAKE (1-800-247-2725)
SR-1
™
Spring
Brake Valve
Service Relay
Valve
QR-1C
®
Quick
Release
Valve
PP-DC
®
Park
Control Valve
Park Co ntrol Valves
The PP-DC
®
park control double check valve is
a push-pull, manually operable on/off valve with an
integral double check. It is dashboard mounted and
provides in-cab control of truck or bus parking brakes.
Manually pushing or pulling the button will release or
apply the parking brakes. The integral double check
valve allows the PP-DC
®
valve to receive supply air
pressure from either, or both, the front or rear axle
service reservoirs.
The valve is pressure sensitive and automatically moves
from the applied (over the road position) to the exhaust
position (thus applying the parking brakes) if total system
pressure (both front and rear axle reservoirs) drops
below 20 to 30 psi.
Section 4: Tractor Parking, Trailer Charging/Parking and
Emergency Systems
The tractor/trailer parking and emergency system typically
consists of:
• The tractor parking control system
• The trailer parking and emergency system, and
• The tractor protection system
See the front covers of this handbook for system schematics.
PP-DC
®
Park
Control Valve
Tractor/Trailer Parking and Emergency Systems
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