How to bleed hydraulic marine steering

Written by will charpentier
  • Share
  • Tweet
  • Share
  • Email

When you have to replace the hoses or rams on your boat's marine hydraulic steering system, you're going to get air into the system. The air occupies space that would otherwise be occupied by hydraulic fluid, which diminishes the operating characteristics of the steering system. The steering mechanism will require more effort and be less responsive to your touch. You can lessen this problem in your boat's steering system by bleeding the air out of it.

Skill level:
Moderately Challenging


  1. 1

    Top off the fluid in your hydraulic system. Entrained air (air molecules trapped between hydraulic fluid molecules) will cause the system to appear full, but as air is bled out of the system, the level of hydraulic fluid will decrease.

  2. 2

    Loosen the port (left) bleed valve on the hydraulic ram by turning it counter-clockwise. The bleed valves are usually located on the fitting where the steering hoses are connected to the ram.

  3. 3

    Turn the boat's steering wheel to port until air stops coming out of the bleed valves on the ram. Hydraulic fluid will come out as you do this, but when the system has been bled, it won't have obvious bubbles in it.

  4. 4

    Close the port bleed valve. Repeat the process for the starboard (right) valve, turning the wheel to starboard.

  5. 5

    Top off the fluid level in the system and repeat the process for both port and starboard fittings until the fluid in the system remains at a constant level.

Tips and warnings

  • You can keep air out of your hydraulics by adding a hydraulic reservoir to your system. This tank will provides a sealed space where entrained air can migrate out of the pressurised fluid.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.