Separate brake release from triple valve operation

Brake release depends on more conditions apart from triple valve state

Author: cesarBLG

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Brakes/MSTS/AirSinglePipe.cs

@@ -424,17 +424,8 @@ public override void Update(float elapsedClockSeconds)
             }
 
             // triple valve set to release pressure in brake cylinder and EP valve set
-            if (TripleValveState == ValveState.Release && HoldingValve == ValveState.Release)
+            if (TripleValveState == ValveState.Release)
             {
-                if (threshold < RetainerPressureThresholdPSI)
-                    threshold = RetainerPressureThresholdPSI;
-                if (AutoCylPressurePSI > threshold)
-                {
-                    AutoCylPressurePSI -= elapsedClockSeconds * ReleaseRatePSIpS;
-                    if (AutoCylPressurePSI < threshold)
-                        AutoCylPressurePSI = threshold;
-                }
-
                 if ((Car as MSTSWagon).EmergencyReservoirPresent)
 				{
                     if (AuxResPressurePSI < EmergResPressurePSI && AuxResPressurePSI < BrakeLine1PressurePSI)
@@ -474,6 +465,15 @@ public override void Update(float elapsedClockSeconds)
                 }
             }
 
+            // Handle brake release: reduce cylinder pressure if all triple valve, EP holding valve and retainers allow so
+            float minCylPressurePSI = Math.Max(threshold, RetainerPressureThresholdPSI);
+            if (TripleValveState == ValveState.Release && HoldingValve == ValveState.Release && AutoCylPressurePSI > minCylPressurePSI)
+            {
+                AutoCylPressurePSI -= elapsedClockSeconds * ReleaseRatePSIpS;
+                if (AutoCylPressurePSI < minCylPressurePSI)
+                    AutoCylPressurePSI = minCylPressurePSI;
+            }
+
             // Charge Auxiliary reservoir for MRP
             if (TwoPipes
                 && (Car as MSTSWagon).DistributorPresent