diff --git a/Software/MainBoard/rust/src/hal/v4_hal.rs b/Software/MainBoard/rust/src/hal/v4_hal.rs
index 1ff4076..fdd4556 100644
--- a/Software/MainBoard/rust/src/hal/v4_hal.rs
+++ b/Software/MainBoard/rust/src/hal/v4_hal.rs
@@ -188,6 +188,8 @@ pub(crate) async fn create_v4(
     let pump_device = I2cDevice::new(I2C_DRIVER.get().await);
     let mut pump_expander = Pca9535Immediate::new(pump_device, 32);
     for pin in 0..8 {
+        let _ = pump_expander.pin_set_low(GPIOBank::Bank0, pin);
+        let _ = pump_expander.pin_set_low(GPIOBank::Bank1, pin);
         let _ = pump_expander.pin_into_output(GPIOBank::Bank0, pin);
         let _ = pump_expander.pin_into_output(GPIOBank::Bank1, pin);
         let _ = pump_expander.pin_set_low(GPIOBank::Bank0, pin);