1881 Dunbier H3073 Mackay Hydraulic Union Copper Gasket | Marine Trailer Part

🔧 Product Description

Dunbier Hydraulic Union Copper Sealing Gasket - Part Number: 1881

A brake-system hydraulic fitting used to seals the matching hydraulic union against the coupling or caliper face. The fitting is dimensioned for the Dunbier/Mackay trailer brake-line system and must be matched by thread, flare type and tube size.

⚙️ Key Features

• Trailer hydraulic brake fitting

• Compatible with the Dunbier/Mackay brake-line family

• Corrosion-resistant brass, plated steel or copper construction as applicable

• Allows service or custom routing of trailer brake plumbing

• Designed for pressure-tight brake-fluid connections

📏 Specifications

• Mackay reference: H3073

• Brake line size and flare type must match the installed system

• Thread must start by hand without force

• Use sealing gasket only where the fitting is designed for one

🔄 Cross Reference & Related Parts

• Dunbier: 1881

• Mackay: H3073

• Related braided brake lines: Dunbier 1893-1901

• Related rigid Bundy tubes: Dunbier 1890-1900

🚤 Trailer Compatibility & Application

• Suits compatible Dunbier hydraulic disc-brake systems

• Not interchangeable with metric, bubble-flare or automotive fittings unless thread and seat are identical

• Inspect mating ports before installation

🔌 Function

Provides a sealed hydraulic connection that seals the matching hydraulic union against the coupling or caliper face.

Common signs of wear or replacement:

• Brake fluid weeps at the fitting

• Threads or flare seat are damaged

• Fitting is cracked, rounded or heavily corroded

• Line cannot be tightened without misalignment

• Air repeatedly enters the system at the joint

🛠️ Installation & Safety

• Use proper flare-nut spanners

• Do not use thread tape on flare-seal fittings

• Replace copper gaskets after disturbance where specified

• Support lines to prevent vibration fatigue

• Pressure-test and bleed the system after service

📦 Condition

• Genuine Dunbier Marine Products trailer component

• Brand new

• Supplied as one hydraulic brake-line fitting

• Supplied in original or equivalent packaging