Glydus Hydraulic Steering System Oil - 1 Litre

The Glydus HOB / HO-150 Hydraulic Steering System Oil is a 1-litre high-viscosity-index mineral hydraulic fluid for compatible marine hydraulic steering systems. It has a viscosity of 15.5 cSt at 40°C, a viscosity index above 150, a -40°C pour point and a flash point above 188°C. Anti-wear, anti-oxidation, anti-foam and anti-corrosion additives support consistent operation across a wide temperature range.

Product Identification

• Brand: Glydus
• Product category: Marine hydraulic steering fluid
• Product name: Hydraulic Steering System Oil
• Primary product code: HOB
• Alternate fluid reference: HO-150
• Fluid designation: Multisteer AWS 15 Hydraulic Oil
• Pack size: 1 litre
• Base-fluid type: High-quality mineral oil
• Viscosity at 40°C: 15.5 cSt
• Viscosity index: Greater than 150
• Pour point: -40°C
• Flash point: Greater than 188°C
• Application: Compatible marine hydraulic steering systems
• Installation types: Inboard and outboard hydraulic steering applications

What Is This Hydraulic Steering Oil Used For?

Glydus HOB / HO-150 is used for filling, servicing and bleeding compatible marine hydraulic steering systems. The fluid transfers hydraulic pressure between the steering helm and hydraulic cylinder, allowing steering-wheel movement to control the boat's steering system.

It is intended for compatible:

• Hydraulic steering helms
• Hydraulic steering cylinders
• Hydraulic steering hoses
• Inboard steering installations
• Outboard steering installations
• Glydus and Multisteer hydraulic steering systems

This product is hydraulic steering fluid and is not intended for use as engine oil, gearbox oil or a general-purpose mechanical steering lubricant.

What Is Included?

The Glydus Hydraulic Steering System Oil is supplied with:

• One 1-litre container of Glydus HOB / HO-150 hydraulic steering fluid

Not included:

• Hydraulic steering helm
• Hydraulic steering cylinder
• Hydraulic steering hoses
• Hydraulic fittings
• Steering-system filling kit
• Bleeding hose or bleed fittings
• Replacement seals or service components

Which Hydraulic Steering Systems Are Compatible?

Glydus HOB / HO-150 is intended for compatible Glydus and Multisteer marine hydraulic steering systems, including suitable inboard and outboard installations.

Before ordering or adding fluid, confirm:

• The steering-system manufacturer specifies mineral hydraulic steering fluid
• The required fluid viscosity matches 15.5 cSt at 40°C
• The required fluid classification is compatible with DIN 51502 HLP or ISO 6743/4 Type HM
• The existing fluid can be mixed with the replacement fluid
• The system does not require a different proprietary, synthetic or automatic-transmission fluid
• One litre is sufficient for the system capacity and bleeding procedure

Compatibility must be determined from the steering-system manual or manufacturer specification. Do not select hydraulic fluid by boat or engine brand alone.

Which Grade and Pack Size Are Supplied?

• Product code HOB: Glydus Hydraulic Steering Fluid
• Alternate reference HO-150: Hydraulic steering oil grade
• Fluid designation: Multisteer AWS 15
• Container size: 1 litre
• Fluid type: Mineral hydraulic oil

This listing covers one 1-litre container. The amount required depends on the steering-system capacity, hose length and volume of fluid displaced during bleeding.

Performance Characteristics

• High-quality mineral base oil
• High viscosity index above 150
• Designed for operation across a wide temperature range
• Reduced viscosity variation as operating temperature changes
• Anti-wear additive protection
• Anti-oxidation additives
• Anti-foam additives
• Anti-corrosion and rust-protection additives
• Non-zinc-based anti-wear additive formulation
• Suitable for compatible marine hydraulic steering applications

The high viscosity index means the fluid is formulated to limit changes in viscosity as temperature changes. This supports more consistent hydraulic response than a low-viscosity-index oil across changing operating conditions.

Anti-foam additives help limit foam formation and entrained air within the fluid. Air in a hydraulic steering system can contribute to excessive steering-wheel movement, inconsistent response and incomplete cylinder travel.

Fluid Properties

• Kinematic viscosity at 40°C: 15.5 cSt
• Viscosity index: Greater than 150
• Pour point: -40°C
• Flash point: Greater than 188°C
• Base oil: Mineral oil
• Additive functions: Anti-wear, anti-oxidation, anti-foam and anti-corrosion
• Nominal fluid designation: AWS 15

The pour point is the stated low-temperature flow characteristic of the oil. It does not independently define the minimum operating temperature of a complete hydraulic steering system.

The flash point is a laboratory property of the fluid and must not be treated as a normal operating-temperature rating.

Hydraulic-Oil Classifications

The available technical data lists the fluid against the following hydraulic-oil classifications:

• DIN 51502: HLP
• ISO 6743/4: Hydraulic oil Type HM

These classifications describe anti-wear mineral hydraulic fluids with oxidation and corrosion protection. The steering-system manufacturer's specified fluid remains the controlling compatibility requirement.

Filling and Bleeding the Steering System

Before filling the steering system:

• Check the steering manufacturer's specified fluid type
• Inspect the helm, cylinder, hoses and fittings for leaks or damage
• Clean the area around the helm filler before opening it
• Prevent water, dirt and other contaminants from entering the system
• Use the filling and bleeding equipment specified for the steering system
• Confirm whether the existing fluid must be drained before adding new oil

During filling and bleeding:

• Follow the helm and cylinder manufacturer's bleeding sequence
• Keep the fluid supply above the minimum level
• Prevent air from being drawn into the helm
• Bleed both sides of the steering cylinder where required
• Continue until the discharged fluid is free from visible air bubbles
• Do not reuse contaminated or previously drained fluid

After bleeding, turn the steering wheel through the complete operating range and check that:

• Steering response is consistent in both directions
• The cylinder reaches its full permitted travel
• There is no excessive free movement at the steering wheel
• Fluid does not leak from the helm, hoses, fittings or cylinder
• The reservoir or helm fluid level remains correct
• All filler plugs and bleed fittings are securely refitted

Marine hydraulic steering is a safety-critical system. Leaks, damaged hoses, contaminated fluid or persistent air in the system must be corrected before the boat is used.

Can This Oil Be Mixed with Existing Steering Fluid?

Do not assume that different hydraulic steering fluids are interchangeable. Before topping up an existing system, identify the fluid already installed and confirm that it is compatible with Glydus HOB / HO-150.

Where the existing fluid cannot be identified, the steering-system manufacturer may require the system to be drained, flushed and refilled with the specified fluid. Mixing incompatible fluids can affect viscosity, additive performance, seal compatibility and steering response.

Storage and Handling

• Store the container upright with the cap securely closed
• Keep the fluid in its original labelled container
• Protect it from water, dirt and other contamination
• Store away from direct heat and ignition sources
• Do not return used or drained fluid to the original container
• Clean spills using an appropriate absorbent material
• Dispose of used hydraulic fluid through an approved waste-oil facility
• Follow the product safety data and local handling requirements

Key Features

• 1-litre marine hydraulic steering fluid
• Glydus product code HOB
• Alternate HO-150 fluid reference
• Multisteer AWS 15 hydraulic oil designation
• High-quality mineral oil formulation
• Suitable for compatible inboard and outboard steering systems
• 15.5 cSt viscosity at 40°C
• Viscosity index greater than 150
• -40°C pour point
• Flash point greater than 188°C
• Wide operating-temperature capability
• Anti-wear additive protection
• Anti-oxidation additives
• Anti-foam additives
• Anti-corrosion and rust-protection additives
• Non-zinc-based anti-wear formulation
• Listed DIN 51502 HLP classification
• Listed ISO 6743/4 Type HM classification
• Steering-system hardware and filling equipment supplied separately