diff --git a/src/hydcoeffs.c b/src/hydcoeffs.c
index 9f4ac3d..e044dff 100644
--- a/src/hydcoeffs.c
+++ b/src/hydcoeffs.c
@@ -691,6 +691,8 @@ void  pumpcoeff(Project *pr, int k)
            hgrad;            // Head loss gradient
     Spump  *pump;
 
+    double qstar;
+
     // Use high resistance pipe if pump closed or cannot deliver head
     setting = hyd->LinkSetting[k];
     if (hyd->LinkStatus[k] <= CLOSED || setting == 0.0)
@@ -748,12 +750,14 @@ void  pumpcoeff(Project *pr, int k)
             if (hgrad > CBIG)
             {
                 hgrad = CBIG;
-                hloss = -hgrad * hyd->LinkFlow[k];
+                qstar = sqrt(-r / hgrad);
+                hloss = (r / qstar) - hgrad * (qstar - q);
             }
             else if (hgrad < hyd->RQtol)
             {
                 hgrad = hyd->RQtol;
-                hloss = -hgrad * hyd->LinkFlow[k];
+                qstar = sqrt(-r / hgrad);
+                hloss = (r / qstar) - hgrad * (qstar - q);
             }
             // ... otherwise compute head loss from pump curve
             else
diff --git a/src/hydstatus.c b/src/hydstatus.c
index 3d7c106..4013ec9 100644
--- a/src/hydstatus.c
+++ b/src/hydstatus.c
@@ -437,12 +437,21 @@ void  tankstatus(Project *pr, int k, int n1, int n2)
     tank = &net->Tank[i];
     if (tank->A == 0.0) return;
 
-    if (hyd->NodeHead[n1] >= tank->Hmax - hyd->Htol && !tank->CanOverflow)
+    // Can't add flow to a full tank
+    if (hyd->NodeHead[n1] >= tank->Hmax && !tank->CanOverflow)
     {
-        if (q < 0.0) hyd->LinkStatus[k] = TEMPCLOSED;
+        if (link->Type == PUMP && link->N2 == n1)
+            hyd->LinkStatus[k] = TEMPCLOSED;
+        else if (q < 0.0)
+            hyd->LinkStatus[k] = TEMPCLOSED;
     }
-    if (hyd->NodeHead[n1] <= tank->Hmin + hyd->Htol)
+
+    // Can't remove flow from an empty tank
+    if (hyd->NodeHead[n1] <= tank->Hmin)
     {
-        if (q > 0.0) hyd->LinkStatus[k] = TEMPCLOSED;
+        if (link->Type == PUMP && link->N1 == n1)
+            hyd->LinkStatus[k] = TEMPCLOSED;
+        else if (q > 0.0)
+            hyd->LinkStatus[k] = TEMPCLOSED;
     }
 }