SeaStar Solutions manufactures the top selling recreational marine hydraulic steering fluid for hydraulic steering systems.

Due to recent upgrades in SeaStar Solutions’ Steering System components,...

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SeaStar Solutions manufactures the top selling recreational marine hydraulic steering fluid for hydraulic steering systems.

Due to recent upgrades in SeaStar Solutions’ Steering System components, SeaStar Solutions recommends using ONLY SeaStar Steering Fluid in their hydraulic steering systems.

About SeaStar Hydraulic Steering Fluid, HA5440H (formerly HA5440)
SeaStar Hydraulic Steering Fluid is engineered with a proprietary additive package which contains:
• Anti-Foaming and Anti-Rusting Agents
• Anti-Oxidants
• Viscosity Stabilizers
• Corrosion Inhibitors
• Wear Additives
• Water Emulsification Additive

SeaStar Hydraulic Steering Fluid is the ONLY steering fluid which is Validated and Performance Matched to ensure the optimum performance and safety of SeaStar Solutions Hydraulic Steering Systems.

SeaStar Hydraulic Steering Fluid can be used in Hynautic, BayStar and BayStar Plus steering systems.

SeaStar Solutions offers a hydraulic fluid filler kit (Part # HA5438) which allows for a clean bleed of a hydraulic steering system when used properly. The kit includes a hose with screw cap which fits SeaStar Hydraulic Steering Fluid Quart sized bottles. Also included is a push pin for venting and resealing the bottle once finished.

NOTE: There is NO difference in the formulation of HA5440 and HA5440H. This is a part number change ONLY and does not affect anything else. Please contact SeaStar Solutions Technical Support at 604-248-3858 with any questions.

Use of any non-approved fluid in a SeaStar Solutions’ Hydraulic Steering System may result in the following:
• Higher steering effort, particularly at ambient or lower temperatures and/or over time due to oil degradation and breakdown
• Increased steering slip and/or drift resulting in lost motion
• Foaming or air entrainment causing a bumpy feel during steering
• High rates of moisture absorption causing internal component corrosion
• Scratched steering cylinder bores and shafts due to contamination or elevated wear rates
• Seal degradation – incompatibility with various proprietary seal compounds used in SeaStar Solutions’ products.


WARNING: Use of non-standard fluids will require an immediate and complete system flush using approved fluids, by an approved steering technician.

WARNING: NEVER FILL OR MIX BRAKE FLUIDS, TRIGLYCERIDES OR POLYALKYLENE GLYCOLS WITHIN A HYDRAULIC STEERING SYSTEM.

NOTICE: Help protect your boating environment by ensuring that all used oil is disposed of properly.



  • SeaStar Hydraulic Steering Fluid is engineered with a proprietary additive package which contains anti-foaming and anti-rusting agents, anti-oxidants, viscosity stabilizers, corrosion inhibitors, wear additives and a water emulsification additive
  • SeaStar Hydraulic Steering Fluid is the ONLY steering fluid which is Validated and Performance Matched to ensure the optimum performance and safety of SeaStar Solutions Hydraulic Steering Systems
  • NOTE: There is no difference in the formulation of HA5440 and HA5440H. This is a part number change ONLY and does not affect anything else
  • SeaStar Solutions offers a hydraulic filler kit (part # HA5458) which allows for a clean bleed of a hydraulic steering system when used properly
  • Due to recent upgrades in SeaStar Solutions' Steering System components, SeaStar Solutions recommends using ONLY SeaStar Steering Fluid in their hydraulic steering systems
  • SeaStar Hydraulic Steering Fluid is engineered with a proprietary additive package which contains anti-foaming and anti-rusting agents, anti-oxidants, viscosity stabilizers, corrosion inhibitors, wear additives and a water emulsification additive
  • SeaStar Hydraulic Steering Fluid is the ONLY steering fluid which is Validated and Performance Matched to ensure the optimum performance and safety of SeaStar Solutions Hydraulic Steering Systems
  • NOTE: There is no difference in the formulation of HA5440 and HA5440H. This is a part number change ONLY and does not affect anything else
  • SeaStar Solutions offers a hydraulic filler kit (part # HA5458) which allows for a clean bleed of a hydraulic steering system when used properly
  • Due to recent upgrades in SeaStar Solutions' Steering System components, SeaStar Solutions recommends using ONLY SeaStar Steering Fluid in their hydraulic steering systems

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