Update flowmeters on trailing locomotives to prevent stuck indications when changing cabs

Author: SteelFill

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

@@ -1276,17 +1276,27 @@ protected static void PropagateBrakeLinePressures(float elapsedClockSeconds, Tra
                     }
                 }
             }
-            // Equalize main reservoir with train pipe for every locomotive
             foreach (TrainCar car in train.Cars)
             {
-                if (car is MSTSLocomotive loco && car.BrakeSystem.TwoPipes)
+                if (car is MSTSLocomotive loco)
                 {
-                    float volumeRatio = loco.BrakeSystem.BrakePipeVolumeM3 / loco.MainResVolumeM3;
-                    float dp = Math.Min((loco.MainResPressurePSI - loco.BrakeSystem.BrakeLine2PressurePSI) / (1 + volumeRatio), loco.MaximumMainReservoirPipePressurePSI - loco.BrakeSystem.BrakeLine2PressurePSI);
-                    loco.MainResPressurePSI -= dp * volumeRatio;
-                    loco.BrakeSystem.BrakeLine2PressurePSI += dp;
-                    if (loco.MainResPressurePSI < 0) loco.MainResPressurePSI = 0;
-                    if (loco.BrakeSystem.BrakeLine2PressurePSI < 0) loco.BrakeSystem.BrakeLine2PressurePSI = 0;
+                    // Continue updating flowmeter on non-lead locomotives so it zeroes out eventually
+                    if (car != lead)
+                    {
+                        (car as MSTSLocomotive).BrakePipeFlowM3pS = 0;
+                        (car as MSTSLocomotive).FilteredBrakePipeFlowM3pS = (car as MSTSLocomotive).AFMFilter.Filter(0, elapsedClockSeconds);
+                    }    
+
+                    // Equalize main reservoir with MR pipe for every locomotive
+                    if (car.BrakeSystem.TwoPipes)
+                    {
+                        float volumeRatio = loco.BrakeSystem.BrakePipeVolumeM3 / loco.MainResVolumeM3;
+                        float dp = Math.Min((loco.MainResPressurePSI - loco.BrakeSystem.BrakeLine2PressurePSI) / (1 + volumeRatio), loco.MaximumMainReservoirPipePressurePSI - loco.BrakeSystem.BrakeLine2PressurePSI);
+                        loco.MainResPressurePSI -= dp * volumeRatio;
+                        loco.BrakeSystem.BrakeLine2PressurePSI += dp;
+                        if (loco.MainResPressurePSI < 0) loco.MainResPressurePSI = 0;
+                        if (loco.BrakeSystem.BrakeLine2PressurePSI < 0) loco.BrakeSystem.BrakeLine2PressurePSI = 0;
+                    }
                 }
             }