True or False: If Parking Bake is applied, then released during pump operations, the hand throttle or pressure governor will be disabled, engine speed will fail to idle, and loss of water pressure will result.

True or False: If Parking Bake is applied, then released during pump operations, the hand throttle or pressure governor will be disabled, engine speed will fail to idle, and loss of water pressure will result.

• A. True
• B. False
• C. Not sure
• D. Not applicable

Answer: (A)

Maintaining a stable engine speed is essential for a fire pump to deliver and hold discharge pressure. The governor and the hand throttle are what keep the pump running at the proper RPM when it’s loaded with water and hoses. When the parking brake is released during pump operations, the control linkage that keeps the pump tied to the engine’s speed can be interrupted. With that control effectively disabled, the engine speed can no longer be reliably held at the required pumping speed. If the engine slows or can’t idle properly under load, the pump can’t develop the necessary pressure, so water pressure in the lines can fall. That is why this situation leads to loss of water pressure and why the statement is true.

Maintaining a stable engine speed is essential for a fire pump to deliver and hold discharge pressure. The governor and the hand throttle are what keep the pump running at the proper RPM when it’s loaded with water and hoses. When the parking brake is released during pump operations, the control linkage that keeps the pump tied to the engine’s speed can be interrupted. With that control effectively disabled, the engine speed can no longer be reliably held at the required pumping speed. If the engine slows or can’t idle properly under load, the pump can’t develop the necessary pressure, so water pressure in the lines can fall. That is why this situation leads to loss of water pressure and why the statement is true.