Under normal conditions drivers should have no reason to operate this valve.
This valve is used to enable the trailer brakes to be released when uncoupled from a towing vehicle for maintenance purposes or for manoeuvring the trailer when the air line is disconnected.
The valve should be pushed to release brakes.
NOTE: The valve is automatically reset when the supply line is connected and pressurised.

PARK VALVE - RED COLOURED KNOB

This valve MUST BE APPLIED, without exception, before uncoupling or coupling the tractor unit.
The valve should be pulled to apply spring brakes and pushed to release spring brakes.

Uncoupling Procedure
Before uncoupling any air lines firstly apply PARK VALVE by pulling RED KNOB outwards. Spring brakes are now applied, continue with normal uncoupling procedure.

Coupling Procedure
Before coupling tractor unit to trailer firstly check that the spring brakes have been applied, i.e. check that the RED KNOB is pulled out.
Continue with the normal coupling procedure, once complete push
RED KNOB inwards to release spring brakes.