Hynautic Steering Parts & Accessories

Hynautic Hydraulic Steering Parts & Accessories

For boaters who have trusted their helm to a hydraulic steering system for decades, the name Hynautic carries serious weight. Hynautic is a renowned name in marine hydraulic steering and engine control systems, and was originally an independent manufacturer before being acquired by Teleflex — now part of SeaStar Solutions — ensuring continued support for its robust product line. That legacy lives on today through a range of steering parts and accessories that keep older Hynautic systems running with precision and reliability.

A Distinct Hydraulic Architecture

What sets Hynautic apart from other marine steering brands is its signature three-line pressurized hydraulic design. Hynautic three-line systems are pressurized and contain a separate reservoir and pressure-relief valve, are common on work and pleasure vessels up to 70 feet, and feature simpler helms since they do not contain the reservoir or relief valve — with fluid fill located at a remote reservoir instead. These systems use soft refrigeration-type copper tubing instead of nylon hose, giving them a distinct and durable character suited to demanding marine environments.

SeaStar offers rugged 3-line Hynautic Heavy Duty steering systems for most work and pleasure vessels up to 70 feet, with heavy-duty helms combining one or two bi-directional axial piston pumps with pilot check and make-up check valving — a design that prevents rudder feedback, operates efficiently even at low RPM, and is immediately adaptable to multi-station use.

Key Steering Components Available

Whether you are restoring a classic inboard cruiser or performing routine maintenance on a commercial vessel, Hynautic steering parts cover the critical components of the hydraulic circuit:

• Helm Pumps: Hynautic's core offerings include manual and power-assisted steering systems engineered for smooth and responsive helm control.
• Hydraulic Cylinders: Hynautic cylinders are available for outboard steering, fixed and pivot mount inboard applications, large inboard configurations, and universal mount inboard setups.
• Tubing & Fittings: Hynautic supplies nylon tubing in 5/16" and 3/8" sizes along with specialized fittings, critical for both older and newer steering installations.
• Relief Valves & Replacement Parts: Many legacy Hynautic steering and control components are compatible with modern SeaStar replacement parts, fittings, tubing, seal kits, and hydraulic accessories.

Wide Vessel Compatibility

Hynautic systems are suitable for most marine engines and hydraulic transmissions, supporting boats up to 100 feet in length. This broad compatibility — spanning recreational boats, sportfishing vessels, trawlers, and commercial fleets — is one reason Hynautic components remain in demand long after the original systems were installed. While original Hynautic systems are largely out of production, critical aftermarket components, high-quality fittings, and hydraulic cylinder seal kits remain widely available for ongoing service and repair.

Maintaining Your Hynautic Steering System

Regular inspection of tubing, fittings, and hydraulic fluid levels is essential for optimal performance and longevity. Keeping the hydraulic circuit sealed and properly filled ensures the system delivers the precise, low-effort helm response Hynautic is known for. If you are sourcing a specific part, note that many legacy Hynautic steering and control components are compatible with modern SeaStar replacement parts, fittings, tubing, seal kits, and hydraulic accessories, making it easier than ever to find what you need to keep your system in top shape.