A combination quick release and service relay brake valve assembly is used
to consolidate multiple valve functions within a common valve assembly,
which reduces cost and overall complexity in an associated vehicle brake
system. The combination quick release and service relay brake valve
assembly includes a valve body with a quick release portion that has a
parking brake port and a service brake control port, which is in fluid
communication with an anti-compounding passage. The valve body also
includes a service relay portion that has a supply port fluidly connected
to a service brake air reservoir and a delivery port fluidly connected to
a brake actuator that generates service brake requests.