Preparation and setup
50
6.4.4
Brake system with combined service/parking brake (Tristop)
Parking and manoeuvring valve with integrated emergency brake valve for the service brake system as
well as overflow valve for auxiliary consumers (e.g. air suspension) for dual-line compressed air brake
systems in trailers. The bake features a flange-mounted release valve as well as a parking valve for the
service and spring-loaded brake. "Parking Hold" is a new additional function with which the service
brake is disengaged when the trailer is coupled while the spring-type cylinders move to or remain in
brake position. Before travel, the spring-type cylinders must be manually released via the parking valve.
Parking brake operation
Pulling the parking valve (
red button
) connects the
spring-loaded brake system to the vent. This
depressurises the spring-loaded brake system and
actuates the parking brake.
Pushing the park valve (
red button
) connects the
spring-loaded brake system to the reservoir, which
builds up the pressure in the spring-loaded brake
system, resulting in the parking brake being
released.
The spring-loaded brake system must always be
released manually following an uncoupling
operation.
However, a release can only take place when the
pressure in the reservoir is at least 5.0 bar.
Release mechanism for service brake system
The release valve allows you to reverse the
automatic ("emergency") braking that is triggered
when the supply line is disconnected.
Pressing the release valve (black button)
– with the
supply/brake line detached
– cancels the automatic
braking of the service brake system. When the
supply line and compressed air are reconnected,
the release valve automatically reverts to its normal
operating position.
Manoeuvring
To manoeuvre the uncoupled vehicle, both buttons
must be pressed
– first black (service brake) and
then red (parking brake). Only then is the
service/parking brake released and the vehicle
unbraked.
After manoeuvring, the park valve (red button) must
be pulled out again (min. 5 bar supply pressure) to
re-apply the parking brake.
Fig. 42
:
Tristop control unit
Fig. 43
:
Tristop operation plate
