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White House Products Ltd - Hydraulic Pump Supplier


Tips for Bleeding Out the Air in Your Hydraulic System

Pneumatic control valve in a steam heating system Before you bleed out the air in your steel tubes and other hydraulic system components, it is important to know whether there is air in your system. If you notice erratic operation with a drop in hydraulic pressure, there is probably air getting into the system somewhere, such as through a cracked hose.

How to Know if Air Is in Your Hydraulic System

  • Check for bubbles in the system. To check for these, look closely at the fluid in the system and see if any bubbles are visible.
  • Listen for a hissing sound. Listen closely for any unusual sounds coming from the system.
  • Check the system pressure. If the system pressure is lower than normal, air may be present.

How Does Air Get Into a Hydraulic System?

Air can enter a hydraulic system in a variety of ways. Common causes include leaks in the system, a poorly sealed filter or reservoir cap, or a malfunctioning pressure relief valve. In some cases, air can enter the system through the hydraulic fluid itself if it is contaminated with water or other contaminants.

How to Bleed Air from a Hydraulic System

  1. Locate the bleed valve. This valve is used to release excess pressure and air from the system.
  2. Open the bleed valve. Open the bleed valve by turning it counterclockwise until it is fully open.
  3. Allow the air to escape. You may notice bubbles in the fluid as the air escapes from the system. Leave the valve open until no more air is visible in the fluid.
  4. Close the bleed valve. Once all the air has been released, close the bleed valve until it is fully closed.
  5. Check the system pressure. Once the bleed valve has been closed, check the system pressure to ensure it is back to normal. If the system pressure is still low, additional bleeding may be necessary.
For dissolved air or “mixed” air where it is in the fluid, you can either increase the temperature of the fluid to release the air or pass the fluid through a gauze screen to remove the air bubbles.

Tips to Use When Bleeding Air Out of Hydraulics

hydraulic system
  • Use the right tools.
  • Work on a level surface.
  • Remove any parts and components that are in your way.
  • Work in a clean environment if possible.
  • Bleed the farthest lines from the pump and work inward.
  • Ensure the fluid reservoir is kept filled as you bleed the lines.

Hydraulic Bleeder Parts and Components

If you need bleeder lines to purge a hydraulic system, tubing, and other related hydraulic parts, components, and pumps, call the hydraulic experts at White House Products, Ltd. by phoning +44 (0) 1475 742500 today!

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