Manual

ManualsBrandsBendix Commercial Vehicle Systems ManualsEquipmenteTrac Automated Air Pressure Transfer System

DEL

SUP

EXH

Bendix

eTrac

™

Automated Air Pressure Transfer System

1. INTRODUCTION

The Bendix

eTrac

™

automated air pressure transfer

system is used on 6 x 2 semi-tractors that feature Bendix

premium and advanced Antilock Brake Systems (ABS).

This system complements the Bendix

Smart ATC

™

(

Automatic Traction Control) feature of our ABS system to

provide improved traction at low speeds (e.g. pulling away

on an inclined ramp, or in slippery conditions such as mud

or snow-covered surfaces, etc.)

SD-13-21021

FIGURE 1 - BENDIX

eTrac

™

SYSTEM WITH SYSTEM COMPONENTS AND A SIMPLE LEVELING SYSTEM SCHEMATIC

Steer axle

Drive axle Tag axle

When needed, the

system provides

the ability to add air

pressure to the drive

axle suspension air

bags, and remove

air pressure from the

tag axle suspension

air bags

See below for labeled

component descriptions

Tag axle

suspension

air bags

(2)

Wheel speed sensors

(All wheel-ends)

Drive axle

suspension

air bags

(2)

Bendix

DC-4

double-check

valve

Bendix

FCS-9700

™

solenoid valve

Bendix

R-12

relay valve

Bendix

brand ABS controller

(Premium or Advanced EC-60 designation or later)

Two Bendix

RV-3

™

valves

Leveling

valve

When active, the Bendix eTrac system vents — or

“dumps” — the air pressure of the tag axle suspension

air bags, and increases the air pressure in the drive axle

suspension air bags to a pre-determined maximum. This

action helps the drive axle to gain more traction.

The air pressure is distributed equally to the

drive and tag axle suspension air bags

DEL

SUP

EXH

Example of a

Simple 6x2

Air Suspension

Leveling

Control System

Leveling

valve

Bendix

brand ABS

controller

(Premium or

Advanced)

Air supply

Summary of content (8 pages)

PAGE 1
SD-13-21021 Bendix® eTrac™ Automated Air Pressure Transfer System Drive axle Steer axle Wheel speed sensors (All wheel-ends) Air supply Tag axle Drive axle suspension air bags (2) Tag axle suspension air bags (2) See below for labeled component descriptions D 4 Bendix® brand ABS controller S E C SUP EXH 1 2 S D D DEL S D (Premium or Advanced) D 5 Leveling valve D 3 When needed, the system provides the ability to add air pressure to the drive axle suspension air bags, and remove air p
PAGE 2
GENERAL SAFETY GUIDELINES WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH: When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES: ▲ Park the vehicle on a level surface, apply the parking brakes and always block the wheels. Always wear personal protection equipment. ▲ Stop the engine and remove the ignition key when working under or around the vehicle.
PAGE 3
. COMPONENTS See Figure 1. See Figure 3. During the Bendix eTrac system Active Mode, the relay valve isolates the rest of the air suspension system from the tag axle suspension air bags and “dumps” the air pressure from them. The air is exhausted through the relay’s exhaust port. See Figure 4. During the Pressure-Limiting Mode, the control port of the “dump” valve receives air pressure from the backfeed valve. This re-inflates the tag axle suspension air bags as required. See Figure 5.
PAGE 4
. OPERATION 4.1 Automatic Mode: Normal Mode. Figure 3 shows the normal system position where the leveling valve controls the delivery of air to the rear axle air suspension bags. Pressure protection valve Air supply D Solenoid valve (OPEN) The leveling valve maintains equal pressure in the drive and tag axle suspension air bags Double check valve EXH SUP DEL EXH Drive axle Tag axle • The solenoid valve remains in the OPEN position; this holds the relay valve in the applied position.
PAGE 5
4.2 Automatic Mode: Bendix® eTrac™ System Active Mode. Figure 4 shows the Bendix eTrac system in its Active Mode where the “dump” valve controls the delivery of air to the rear axle suspension air bags. This diagram is for both automatic and semi-automatic applications.
PAGE 6
4.3 Automatic Mode: Bendix® eTrac™ System Active Mode with Pressure-Limiting Mode. Figure 5 shows the Bendix eTrac system in its Pressure-Limiting Mode.
PAGE 7
5. TROUBLESHOOTING Since this system uses some familiar valves for special purposes, the troubleshooting guide is presented in a frequently-asked-questions format: Q: The Bendix® RV-3™ valve used for the backfeed function seems to be incorrectly plumbed on the vehicle (and in this document). Why? A: To support special Bendix® eTrac™ system functions, it is correct that the backfeed valve has its delivery port connected to the leveling valve delivery port.
PAGE 8
www.bendix.com For the latest information, and for free downloads of literature and the Bendix® ACom® diagnostics software, and its User Guide, visit the Bendix website at www.bendix.com. Bendix Technical Assistance Team For technical support, call the Bendix technical assistance team at 1-800-AIR-BRAKE (1‑800‑247-2725), Monday through Friday, 8:00 a.m. to 6:00 p.m. ET. Alternatively, you may e-mail the Bendix Tech Team at: techteam@bendix.com.