BENDIX R-12-R-14 RELAY VALVES User Manual

1
Bendix
®
R-12
™
& R-14
™
Relay Valves
DESCRIPTION
The relay valve in an air brake system functions as a relay
station to speed up the application and release of the brakes.
The valve is normally mounted at the rear of the vehicle in
proximity to the chambers it serves. The valve operates as a
remote controlled brake valve that delivers or releases air to
the chambers in response to the control air delivered to it
from the foot brake valve or other source.
The R-12
™
and R-14
™
relay valves are designed for either
reservoir or frame mounting. A universal mounting bracket is
furnished that permits easy interchange with other Bendix
relay valves. Both valves are available in the two body styles
illustrated in Figure 1. The R-14
™
valve differs from the
R-12
™
valve in that it incorporates a quick release and anti-
compounding feature located above its horizontal service
port. The R-14
™
valve’s anti-compound feature allows it to
be conveniently used as either a service or spring brake
relay valve. An exhaust cover is installed that protects the
1/8" balance port when the R-14
™
valve anti-compound
feature is not in use.
FIGURE 1 - EXTERIOR VIEWS
EXTERIOR R-14HEXTERIOR R-12H
SERVICE (1)
SUPPLY (2)
DELIVERY
SERVICE (1)
DELIVERY
SUPPLY (2)
EXTERIOR R-12V
EXTERIOR R-14V
SD-03-1064
DELIVERY
DELIVERY
SUPPLY

BENDIX R-12-R-14 RELAY VALVES Specifications

General

Brand	BENDIX
Model	R-12-R-14 RELAY VALVES
Category	Control Unit
Language	English

Summary

Description of Relay Valves

Valve Operation and Features

Application Process

Describes how air pressure applied to the service port moves the piston down to apply brakes.

Pressure Balance Mechanism

Explains how the valve maintains brake application by balancing air pressures.

Exhaust or Release Function

Details how releasing pressure from the service port allows brake release.

Anti-Compounding Feature

Explains the R-14 valve's anti-compound feature for simultaneous service/park brake applications.

Preventive Maintenance Schedule

Recommends inspection intervals for valve operation and performance.

Operational and Leakage Testing

Removal, Disassembly, and Cleaning

Valve Removal Procedure

Steps for safely removing the relay valve from the vehicle's air brake system.

Disassembly Instructions

Detailed steps for taking the valve apart for internal servicing.

Cleaning and Inspection Guide

Procedures for cleaning metal parts and inspecting for wear or damage.

Assembly and Installation

Assembly Steps

Instructions for reassembling the relay valve components after servicing.

Installation on Vehicle

Guidance on properly installing the assembled valve onto the vehicle.

Critical Safety Precautions