Description

Overview

This Pacific relay valve supports long wheelbase trailer braking systems, and R-8 relay valve provides fast air transfer to rear service and spring brakes for consistent response in heavy trailer combinations.

Features

This R-8 relay valve uses a balance port under the exhaust cover so it can provide anti compounding control or quick exhaust, depending on plumbing. It also incorporates an internal double check valve to manage multiple control signals and maintain stable brake timing.

Specifications and Materials

Model: suits R-8 relay valve applications with balance port under the exhaust cover and 90 degree port rotation at the service connection. Control port: 1/4 inch pipe thread. Supply ports: two 3/4 inch ports plus one 1/4 inch auxiliary port. Delivery ports: two 1/2 inch ports. Balance port: 1/8 inch located under the exhaust cover. Crack pressure: 3 psi. Part number: AB8351. For detailed technical data on this R-8 design, refer to this manufacturer technical guide for Bendix R-8 relay valves.

Compatibility and Fitment

This cross-reference listing means this valve is a suitable replacement for the part numbers and applications shown. Some changes in air line plumbing may be required. 286370, 286370R, 286371, 288221, 286371X, 287277, 289795, 287277X, RKN28071, 22A2696, 825735, 101930, 10130548, 9069725, KN28071, 763353, AE763353, 936750, 1676729C1, 666969C91, 90001269, 90002279, S9174, 110412, 110416, 24693, 36U94D1, 4017724, 034024, 1092945, 1690499, 79105006, R8.

Compliance and Safety

When you install this relay valve in a heavy trailer brake system, you maintain fast air delivery to the rear axles so the foundation brakes respond evenly. Always follow the trailer or axle manufacturer’s service instructions and use approved air brake practices. In addition, pressure test the system after installation to confirm there are no leaks.

Trailer Applications

Fleet operators use the R-8 relay valve on heavy trailers with spring brake chambers and long service lines where response time matters. It suits applications where the relay valve mounts close to the rear axle group to reduce air line length and improve timing.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

Check the existing valve casting and plumbing layout against these references to confirm suitability before committing to a full changeover.

Why Choose ICS Trailers

ICS Trailers supplies relay valves and air brake components that suit the demands of Australian heavy trailers, so you can match parts confidently to your fleet. Additionally, the team can help cross check existing valve numbers and port layouts where required. For matching valves, fittings and airlines, browse Air Brake Parts at ICS Trailers