Bendix R8 Style Relay Valve 288755 | Forestry Yarder & Air Brake Valve

The Bendix R8  Relay Valve (288755) is a high-capacity, fast-response pneumatic relay valve equipped with an integral double check valve. Engineered specifically for logging yarders (Madill, Skagit, Thunderbird), winch drum brake actuators, and heavy-haul carrier chassis, the R-8 valve regulates high-volume air signals while providing built-in anti-compounding protection. Features a heavy-duty cast alloy housing, integrated 2-bolt flange mount, high-volume supply/delivery ports, and a debris-protected lower exhaust.

Bendix R8 Relay Valve 288755 | Forestry Yarder & Air Brake Valve

Maximize pneumatic response, safety, and operational control on logging yarders, winch drums, and heavy forestry carriers with the Bendix R-8 Style Relay Valve. Engineered to replace Bendix 288755 and Newstar S-A498 assemblies, this high-flow graduating air control valve delivers rapid pressure application and instant release for high-volume brake chambers and pneumatic drum actuators.

Yarder Winch Drum & Interlock Control

On logging yarders, standard operator cab controls cannot deliver compressed air fast enough through long pneumatic lines to instantly lock or disengage heavy drum band and disc brakes. The Bendix R-8 Relay Valve mounts directly near the winch frame, using low-volume control signals from the operator console to instantly release full reservoir pressure into main, haulback, or guylinet drum brake actuators. Its integral double check valve manages dual-control signal inputs without allowing air to backfeed into secondary control lines.

Carrier Undercarriage Anti-Compounding

For mobile yarder carrier undercarriages and heavy logging transport rigs, the R-8 functions as the primary rear axle anti-compounding relay valve. Its internal double check mechanism prevents simultaneous application of service brake air pressure and mechanical spring parking brakes, preventing snapped brake shoes, damaged drums, and structural linkage failures on steep haul roads.

Heavy-Duty Logging Construction

Constructed with a precision-machined aluminum alloy housing, the valve features a low 5 PSI nominal crack pressure for rapid signal actuation. It incorporates a lower exhaust port fitted with a protective rubber umbrella disc to seal out wood chips, forest dust, mud, and moisture during continuous field operation.

Technical Specifications