Description

Overview

The Bendix Trailer Relay Emergency Valve serves heavy trailer and dolly air brake systems. It combines relay and emergency functions to speed service brake response and to apply trailer brakes automatically if supply pressure drops.

Features

• Dual-function design for relay and emergency control
• Piston-operated mechanism for consistent response
• Clearly identified service, delivery, supply, exhaust and reservoir ports
• Proven Bendix design used widely on trailers and converter dollies

Specifications and Materials

Part number: AB8502.
Function: Relay and emergency operation; the valve typically mounts to a flange or reservoir.
Body: Cast aluminium alloy with a serviceable valve cartridge.
Typical application: Trailer and dolly brake systems that require fast service response and reliable emergency application. For detailed operation and service procedures, see the Bendix service data sheet SD-03-1151 manufacturer technical guide.

Compatibility and Fitment

Use this relay emergency valve on pre-121 trailer layouts and on current off-highway trailer and converter dolly systems. Install it with the correct porting to service, delivery, supply and reservoir lines according to the vehicle’s pneumatic diagram.

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.
281865, 281865R, 101197, 101197X, 281860514658, 846938, 281672F, 284280, R955281865, 281672, 281864, 281862, 285708, 283034, 284103, 288724, 5001242, 7J7235, E4037833, M1567182, M2511014, 48206099, 1663363, 16A63363, 4037833, EBN281865N, 7271, ACC049418, AND91477, ARA32601, 6B277445, 2471955, 9016927, 9018245, 4900093, 37025, 83073240, 41188, 41308, KN30400, 31A1631, 50652874, 281865B1, 10TN856, 3TN420, S7558, 110268, 110470, 401130, 1936001006, 936001004, 14033, 1019237, 1019238, 9049029, 9051594, 38072, 4017762, 4184001, 034029, 1092941, 1998530001, 21406050

Compliance and Safety

Before you return the trailer to service, use only clean, dry air and follow OEM torque and plumbing practices. Then perform leak checks and confirm correct parking and service brake operation during static and dynamic tests.

Trailer Applications

For example, you will commonly find this valve on semi-trailers, pig trailers and converter dollies where it speeds service brake actuation and provides emergency protection if supply pressure is lost.

Cross-reference and Suitability

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

Why Choose ICS Trailers

We supply proven Bendix air brake components and provide knowledgeable support. Additionally, our team helps you match valves to your trailer system so you can install with confidence and keep fleets on the road. Browse Air Brake Parts at ICS Trailers