ABS. L20555 Rev 6/09. Your ABS Superstore

(1)

Your ABS Superstore

ABS

L20555 Rev 6/09

What do the “S” and “M” stand for when used to describe an ABS System such as 2S/1M?

The “S” is a convention used to denote the sensors in an ABS system, while the “M” refers to the modulator valves. Describing an

ABS system as 2S/1M simply means that it uses 2 sensors and 1 modulator valve. The basic 2S/1M system is used to monitor two

sensors attached to each wheel end of one axle, which is controlled by one modulator valve that receives instructions from an

electronic brain called an ECU.

Why would one use a 4S/2M system on a trailer instead of the basic 2S/1M system?

The configuration of an ABS system typically depends upon the intended use of the trailer unit. While a 2S/1M system may meet the

minimum legal requirements, geographic road conditions can make a 4S/2M system more logical by offering added control of two

axles independently or side-by-side control of the trailer. Full type trailers require 4S/2M systems.

What makes tractor and trailer ABS systems different?

Many modern tractor ABS systems use 4S/4M systems, and others can be 6S, depending upon the number of sensors used and the

number of axles present on the tractor unit. Trailers, on the other hand, typically employ a 2S/1M system with sensors present on

only one axle.

How does a trailer ABS system function with two tanks?

Historically, two tanks have been used on trailers to protect pressures and ensure that the braking system would have charged air.

However, due to the modern 8x air volume requirement, a single jumbo tank could be used. The use of two tanks is still typically

used in applications where there are tight spaces, or a number of auxiliary devices are used.

On which axles should I install my ABS sensors?

ABS sensor location ultimately depends upon whether the trailer is equipped

with spring or air suspension. Typically, with spring suspension, sensors

should be installed in the axle furthest forward on the trailer, while with

air suspension, sensors should be installed to the rear axle in

double-axle units and the middle double-axle of triple double-axle units. The general

principal is to attach the sensors to the axle, or wheel ends,

that are most likely to lockup during a hard

braking event.

On which tank should I install my ABS valve?

As a general rule, valves should be installed centrally on a trailer. In other words, the tank that is closer to the center of the trailer in

terms of length of plumbing lines, should receive the valve. The reason for this is simply to ensure proper brake timing and balance.

ABS Basics - A Review

Need more information?

For more details regarding Haldex ABS

Systems, refer to L30041 ABS Manual or

Contact the Haldex Technical Services

Department at 800-643-2374.

L20555 US Rev 6/09 5M ??

Haldex Limited

525 Southgate Drive, Unit 1

Guelph, Ontario CAN N1G 3W6

Phone: 519-826-7723

Fax: 519-826-9497

Haldex Brake Products Corporation

10930 N. Pomona Ave.

Kansas City, MO 64153-1256

Phone: 816-891-2470

Fax: 816-891-9447

www.haldex.com

Haldex Commercial Vehicle Systems

Haldex Part #

Package Contents

4725003000X

1 psi Press. Diff. Screw-In connector

4721950800X Modulator Valve - L 4721950810X Modulator Valve - R 9735001040X Quick Release Valve

4725003010X

3-4 psi Press. Diff. Screw-In connector

4725003020X

4725003200X

1 psi Press. Diff. Bayonet connector

4725003210X

3-4 psi Press. Diff. Bayonet connector

4725003220X

NOTE:

• Valve Package Assemblies are usually attached to a frame cross-member.

• All systems shown are 12 Volt. • These ABS axle valve packs listed are compatible with C, D and E Versions of Meritor/Wabco ECU’s.

• Use the following converter cables to switch connector styles: Screw to Bayonet (8946011322K) / Bayonet to Screw (8946011332K)

SKU #

Product Description

System Configuration

Connector Type

4721950050X Reman. Modulator Valve in Line Style One Delivery 180° from Supply Screw-in

4721950520X Reman. Modulator Valve in Line Style One Delivery 180° from Supply Bayonet

4721950760X Reman. Modulator Valve - Left 4S/4M Bayonet

4721950770X Reman. Modulator Valve - Right 4S/4M Bayonet

4721950780X Reman. Modulator Valve - Left 4S/4M, 6S/4M or 6S/6M Bayonet

4721950790X Reman. Modulator Valve - Right 4S/4M, 6S/4M or 6S/6M Bayonet

4721950800X Reman. Modulator Valve - Left 4S/4M Screw-in

4721950810X Reman. Modulator Valve - Right 4S/4M Screw-in

4721950820X Reman. Modulator Valve - Left 4S/4M, 6S/4M or 6S/6M Screw-in

4721950830X Reman. Modulator Valve - Right 4S/4M, 6S/4M or 6S/6M Screw-in

4721950920X Reman. Modulator Valve in Line Style One Delivery 90° to left of Supply & One 180° Screw-in

4721950930X Reman. Modulator Valve in Line Style One Delivery 90° to right of Supply & One 180° Screw-in

4721950940X Reman. Modulator Valve in Line Style One Delivery 90° to left of Supply & One 180° Bayonet

4721950950X Reman. Modulator Valve in Line Style One Delivery 90° to right of Supply & One 180° Bayonet

Remanufactured Truck/Tractor ABS

Reman Meritor Wabco Style

Screw-In

Connector

Type

Bayonet

Connector

Type

Modulcator V

alves

Complete F

ront Axle V

alve P

acks

Haldex Part #

Package Contents

9730110210X Meritor WABCO Style ABS Relay Valve

9735001040X Meritor WABCO Style ABS QR Valve

V

alves

Haldex Part #

Package Contents

4725001000X

4721950800X Modulator Valve - L 4721950810X Modulator Valve - R 9730110210X Service Brake Relay Valve

4725001010X

5.5 psi Press. Diff. Screw-In connector

4725001020X

4 psi Press Diff. Screw-in connector

4721950820X Modulator Valve -L 4721950830X Modulator Valve - R 9730110210X Service Brake Relay Valve

4725001030X

5.5 psi Press Diff. Screw-in connector

4725001200X

4725001210X

5.5 psi Press. Diff. Bayonet connector

4725001220X

4 psi Press Diff. Bayonet connector

4725001230X

5.5 psi Press Diff. Bayonet connector

4725001240X

4725001250X

4725002030X

4721950820X Modulator Valve - L 4721950830X Modulator Valve - R 9730110260X Service Brake Relay Valve 4721707910X ATC Valve

4725002220X

4725002230X

4725002240X

4725002250X

Complete Rear Axle V

alve P

(2)

We’re the Stop for ABS

ABS

Haldex

Part Number

Key Kit Contents

AQ960503

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960510

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960514

_{bracket, 19.7 ft Power Cable Extensions, 8.2 ft Sensors}

4-port Valve/ECU Combo with back style mounting

AQ964110

12 Volt ECU/ECU Bracket, 3.3 ft Power Cable

Extensions, Sensor Extensions

ABS Application

Multi-Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

All Competitive

2S/1M Systems

Part Number

Haldex

Key Kit Contents

Bosch

Haldex

Meritor/Wabco

Wabash

AQ960505

2-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

ABS Application

Single or

Dolly Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

Symbol Key

Haldex All-Makes Trailer

ABS Replacement Kits

2S/1M Multi-Axle

2S/1M Tandem Dolly

2S/1M Single-Axle

2S/1M Multi-Axle

Power Cords

Haldex Part #

Power Cord Length

ABS Lamp Lead Length

AL918600*

AL918601*

AL918602

AL918603

AL918604

AL918605

AL918606

65.6 ft (20.0 m)

39.4 ft (12.0 m)

65.6 ft (20.0 m)

39.4 ft (12.0 m)

52.5 ft (16.0 m)

59.1 ft (18.0 m)

16.0 ft (5.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

10.0 ft (3.0 m)

Haldex Part #

ABS Replacement Component Description

AL919900

AL919901

AL919902

6.6 ft

(2.0 m)

13.1 ft

(4.0 m)

19.7 ft

(6.0 m)

Power Cord Extensions

Haldex Part #

ABS Replacement Component Description

A59512309

A902700

A902701

A902702

AL920809

AL920810

Sensor retainer clip

Sensor / lead retainer

Sensor to 3/4” O.D. hose (1/2” I.D.)

Sensor to 1/2” O.D. hose (3/8” I.D.)

Sensor to hose (Haldex O.D.)

Clips/Retainers

Haldex Part #

ABS Replacement Component Description

AQ15463

A1017316

A920805

AQ15473

AQ15474

ABS lamp kit with 6” lead

ABS round indicator lamp (10 series)

Bracket for round ABS lamp

Power cord 5-way terminal kit

Loom assembly 5-way terminal kit

Lamps/Cord End Kits

Haldex All-Makes ABS Components

ABS Care Kit Part #: AQ961110

Haldex Part

#

ABS Replacement Component

Description

Qty.

AQ15474

AQ15473

AQ15463

AL10271914

AL10271915

AL1027196

AL919803

A902700

AL920809

L60050

L20243

Loom Assembly Repair Kit

Power Cord End Kit

ABS Warning Light Kit

Sensor — 90° Body —18”

Sensor — 90° Body —72”

Sensor — Straight Body — 18”

Sensor Extension — 72”

Retainer — Sensor Cable to Lead

Sensor Clip

All-Makes ABS Repair Parts Wall Chart

Trailer ABS Service Components Catalog

1

2

1

2

4

10

1

1 ABS Sensors

Sensor with

90° Ends

Sensor with

Straight Ends

Haldex Part #

Component Description

AL10271914

AL364061

AL10271915

AL364062

AL364063

AL364053

1.6 ft

(0.5 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

AL1027196

AL1027197

1.6 ft

(0.5 m)

6.6 ft

(2.0 m)

Sensor Cable

Extensions

Haldex Part #

Component Description

AL919800

AL919801

AL919802

AL919803

AL919804

AL919805

AL919806

AL919807

AL919808

AL919809

AL919810

AL919811

1.6 ft

(0.5 m)

3.3 ft

(1.0 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

9.8 ft

(3.0 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

16.4 ft

(5.0 m)

19.7 ft

(6.0 m)

26.2 ft

(8.0 m)

32.8 ft

(10.0 m)

Sensor Cable Extensions

All Makes. All Models

*

Pre-2001 systems

Notes: Do NOT interchange with Bendix

®

_{. Haldex sensors have a resistance range}

of 980 - 2350

Ω (OHMS).

Notes: Do NOT interchange with Bendix

®

_.

Be sure to check out our selection of Remanufactured

Truck and Tractor ABS on the back of this brochure

All Competitive

2S/1M Systems

Bosch

Haldex

Meritor/Wabco

Wabash

Wabash MBS

Upgrade Kit

(3)

We’re the Stop for ABS

ABS

Haldex

Part Number

Key Kit Contents

AQ960503

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960510

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960514

_{bracket, 19.7 ft Power Cable Extensions, 8.2 ft Sensors}

4-port Valve/ECU Combo with back style mounting

AQ964110

12 Volt ECU/ECU Bracket, 3.3 ft Power Cable

Extensions, Sensor Extensions

ABS Application

Multi-Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

All Competitive

2S/1M Systems

Part Number

Haldex

Key Kit Contents

Bosch

Haldex

Meritor/Wabco

Wabash

AQ960505

2-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

ABS Application

Single or

Dolly Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

Symbol Key

Haldex All-Makes Trailer

ABS Replacement Kits

2S/1M Multi-Axle

2S/1M Tandem Dolly

2S/1M Single-Axle

2S/1M Multi-Axle

Power Cords

Haldex Part #

Power Cord Length

ABS Lamp Lead Length

AL918600*

AL918601*

AL918602

AL918603

AL918604

AL918605

AL918606

65.6 ft (20.0 m)

39.4 ft (12.0 m)

65.6 ft (20.0 m)

39.4 ft (12.0 m)

52.5 ft (16.0 m)

59.1 ft (18.0 m)

16.0 ft (5.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

10.0 ft (3.0 m)

Haldex Part #

ABS Replacement Component Description

AL919900

AL919901

AL919902

6.6 ft

(2.0 m)

13.1 ft

(4.0 m)

19.7 ft

(6.0 m)

Power Cord Extensions

Haldex Part #

ABS Replacement Component Description

A59512309

A902700

A902701

A902702

AL920809

AL920810

Sensor retainer clip

Sensor / lead retainer

Sensor to 3/4” O.D. hose (1/2” I.D.)

Sensor to 1/2” O.D. hose (3/8” I.D.)

Sensor to hose (Haldex O.D.)

Clips/Retainers

Haldex Part #

ABS Replacement Component Description

AQ15463

A1017316

A920805

AQ15473

AQ15474

ABS lamp kit with 6” lead

ABS round indicator lamp (10 series)

Bracket for round ABS lamp

Power cord 5-way terminal kit

Loom assembly 5-way terminal kit

Lamps/Cord End Kits

Haldex All-Makes ABS Components

ABS Care Kit Part #: AQ961110

Haldex Part

#

ABS Replacement Component

Description

Qty.

AQ15474

AQ15473

AQ15463

AL10271914

AL10271915

AL1027196

AL919803

A902700

AL920809

L60050

L20243

Loom Assembly Repair Kit

Power Cord End Kit

ABS Warning Light Kit

Sensor — 90° Body —18”

Sensor — 90° Body —72”

Sensor — Straight Body — 18”

Sensor Extension — 72”

Retainer — Sensor Cable to Lead

Sensor Clip

All-Makes ABS Repair Parts Wall Chart

Trailer ABS Service Components Catalog

1

2

1

2

4

10

1

1 ABS Sensors

Sensor with

90° Ends

Sensor with

Straight Ends

Haldex Part #

Component Description

AL10271914

AL364061

AL10271915

AL364062

AL364063

AL364053

1.6 ft

(0.5 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

AL1027196

AL1027197

1.6 ft

(0.5 m)

6.6 ft

(2.0 m)

Sensor Cable

Extensions

Haldex Part #

Component Description

AL919800

AL919801

AL919802

AL919803

AL919804

AL919805

AL919806

AL919807

AL919808

AL919809

AL919810

AL919811

1.6 ft

(0.5 m)

3.3 ft

(1.0 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

9.8 ft

(3.0 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

16.4 ft

(5.0 m)

19.7 ft

(6.0 m)

26.2 ft

(8.0 m)

32.8 ft

(10.0 m)

Sensor Cable Extensions

All Makes. All Models

*

Pre-2001 systems

Notes: Do NOT interchange with Bendix

®

_{. Haldex sensors have a resistance range}

of 980 - 2350

Ω (OHMS).

Notes: Do NOT interchange with Bendix

®

_.

Be sure to check out our selection of Remanufactured

Truck and Tractor ABS on the back of this brochure

All Competitive

2S/1M Systems

Bosch

Haldex

Meritor/Wabco

Wabash

Wabash MBS

Upgrade Kit

(4)

We’re the Stop for ABS

ABS

Haldex

Part Number

Key Kit Contents

AQ960503

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960510

6-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

AQ960514

_{bracket, 19.7 ft Power Cable Extensions, 8.2 ft Sensors}

4-port Valve/ECU Combo with back style mounting

AQ964110

12 Volt ECU/ECU Bracket, 3.3 ft Power Cable

Extensions, Sensor Extensions

ABS Application

Multi-Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

All Competitive

2S/1M Systems

Part Number

Haldex

Key Kit Contents

Bosch

Haldex

Meritor/Wabco

Wabash

AQ960505

2-port Valve/ECU Combo, 19.7 ft Power Cable

_{Extensions, Sensor Extensions}

ABS Application

Single or

Dolly Axle

2S/1M Applications

12 Volt

1/2” Reservoir Port

Symbol Key

Haldex All-Makes Trailer

ABS Replacement Kits

2S/1M Multi-Axle

2S/1M Tandem Dolly

2S/1M Single-Axle

2S/1M Multi-Axle

Power Cords

Haldex Part #

Power Cord Length

ABS Lamp Lead Length

AL918600*

AL918601*

AL918602

AL918603

AL918604

AL918605

AL918606

65.6 ft (20.0 m)

39.4 ft (12.0 m)

65.6 ft (20.0 m)

39.4 ft (12.0 m)

52.5 ft (16.0 m)

59.1 ft (18.0 m)

16.0 ft (5.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

26.2 ft (8.0 m)

39.4 ft (12.0 m)

10.0 ft (3.0 m)

Haldex Part #

ABS Replacement Component Description

AL919900

AL919901

AL919902

6.6 ft

(2.0 m)

13.1 ft

(4.0 m)

19.7 ft

(6.0 m)

Power Cord Extensions

Haldex Part #

ABS Replacement Component Description

A59512309

A902700

A902701

A902702

AL920809

AL920810

Sensor retainer clip

Sensor / lead retainer

Sensor to 3/4” O.D. hose (1/2” I.D.)

Sensor to 1/2” O.D. hose (3/8” I.D.)

Sensor to hose (Haldex O.D.)

Clips/Retainers

Haldex Part #

ABS Replacement Component Description

AQ15463

A1017316

A920805

AQ15473

AQ15474

ABS lamp kit with 6” lead

ABS round indicator lamp (10 series)

Bracket for round ABS lamp

Power cord 5-way terminal kit

Loom assembly 5-way terminal kit

Lamps/Cord End Kits

Haldex All-Makes ABS Components

ABS Care Kit Part #: AQ961110

Haldex Part

#

ABS Replacement Component

Description

Qty.

AQ15474

AQ15473

AQ15463

AL10271914

AL10271915

AL1027196

AL919803

A902700

AL920809

L60050

L20243

Loom Assembly Repair Kit

Power Cord End Kit

ABS Warning Light Kit

Sensor — 90° Body —18”

Sensor — 90° Body —72”

Sensor — Straight Body — 18”

Sensor Extension — 72”

Retainer — Sensor Cable to Lead

Sensor Clip

All-Makes ABS Repair Parts Wall Chart

Trailer ABS Service Components Catalog

1

2

1

2

4

10

1

1 ABS Sensors

Sensor with

90° Ends

Sensor with

Straight Ends

Haldex Part #

Component Description

AL10271914

AL364061

AL10271915

AL364062

AL364063

AL364053

1.6 ft

(0.5 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

AL1027196

AL1027197

1.6 ft

(0.5 m)

6.6 ft

(2.0 m)

Sensor Cable

Extensions

Haldex Part #

Component Description

AL919800

AL919801

AL919802

AL919803

AL919804

AL919805

AL919806

AL919807

AL919808

AL919809

AL919810

AL919811

1.6 ft

(0.5 m)

3.3 ft

(1.0 m)

4.9 ft

(1.5 m)

6.6 ft

(2.0 m)

8.2 ft

(2.5 m)

9.8 ft

(3.0 m)

11.5 ft

(3.5 m)

13.1 ft

(4.0 m)

16.4 ft

(5.0 m)

19.7 ft

(6.0 m)

26.2 ft

(8.0 m)

32.8 ft

(10.0 m)

Sensor Cable Extensions

All Makes. All Models

*

Pre-2001 systems

Notes: Do NOT interchange with Bendix

®

_{. Haldex sensors have a resistance range}

of 980 - 2350

Ω (OHMS).

Notes: Do NOT interchange with Bendix

®

_.

Be sure to check out our selection of Remanufactured

Truck and Tractor ABS on the back of this brochure

All Competitive

2S/1M Systems

Bosch

Haldex

Meritor/Wabco

Wabash

Wabash MBS

Upgrade Kit

(5)

Your ABS Superstore

ABS

L20555 Rev 6/09

What do the “S” and “M” stand for when used to describe an ABS System such as 2S/1M?

The “S” is a convention used to denote the sensors in an ABS system, while the “M” refers to the modulator valves. Describing an

ABS system as 2S/1M simply means that it uses 2 sensors and 1 modulator valve. The basic 2S/1M system is used to monitor two

sensors attached to each wheel end of one axle, which is controlled by one modulator valve that receives instructions from an

electronic brain called an ECU.

Why would one use a 4S/2M system on a trailer instead of the basic 2S/1M system?

The configuration of an ABS system typically depends upon the intended use of the trailer unit. While a 2S/1M system may meet the

minimum legal requirements, geographic road conditions can make a 4S/2M system more logical by offering added control of two

axles independently or side-by-side control of the trailer. Full type trailers require 4S/2M systems.

What makes tractor and trailer ABS systems different?

Many modern tractor ABS systems use 4S/4M systems, and others can be 6S, depending upon the number of sensors used and the

number of axles present on the tractor unit. Trailers, on the other hand, typically employ a 2S/1M system with sensors present on

only one axle.

How does a trailer ABS system function with two tanks?

Historically, two tanks have been used on trailers to protect pressures and ensure that the braking system would have charged air.

However, due to the modern 8x air volume requirement, a single jumbo tank could be used. The use of two tanks is still typically

used in applications where there are tight spaces, or a number of auxiliary devices are used.

On which axles should I install my ABS sensors?

ABS sensor location ultimately depends upon whether the trailer is equipped

with spring or air suspension. Typically, with spring suspension, sensors

should be installed in the axle furthest forward on the trailer, while with

air suspension, sensors should be installed to the rear axle in

double-axle units and the middle double-axle of triple double-axle units. The general

principal is to attach the sensors to the axle, or wheel ends,

that are most likely to lockup during a hard

braking event.

On which tank should I install my ABS valve?

As a general rule, valves should be installed centrally on a trailer. In other words, the tank that is closer to the center of the trailer in

terms of length of plumbing lines, should receive the valve. The reason for this is simply to ensure proper brake timing and balance.

ABS Basics - A Review

Need more information?

For more details regarding Haldex ABS

Systems, refer to L30041 ABS Manual or

Contact the Haldex Technical Services

Department at 800-643-2374.

L20555 US Rev 6/09 5M ??

Haldex Limited

525 Southgate Drive, Unit 1

Guelph, Ontario CAN N1G 3W6

Phone: 519-826-7723

Fax: 519-826-9497

Haldex Brake Products Corporation

10930 N. Pomona Ave.

Kansas City, MO 64153-1256

Phone: 816-891-2470

Fax: 816-891-9447

www.haldex.com

Haldex Commercial Vehicle Systems

Haldex Part #

Package Contents

4725003000X

4725003010X

4725003020X

4725003200X

4725003210X

4725003220X

NOTE:

SKU #

Product Description

System Configuration

Connector Type

Remanufactured Truck/Tractor ABS

Reman Meritor Wabco Style

Screw-In

Connector

Type

Bayonet

Connector

Type

Modulcator V

alves

Complete F

ront Axle V

alve P

acks

Haldex Part #

Package Contents

V

alves

Haldex Part #

Package Contents

4725001000X

4725001010X

4725001020X

4725001030X

4725001200X

4725001210X

4725001220X

4725001230X

4725001240X

4725001250X

4725002030X

4725002220X

4725002230X

4725002240X

4725002250X

Complete Rear Axle V

alve P

(6)

Your ABS Superstore

ABS

L20555 Rev 6/09

What do the “S” and “M” stand for when used to describe an ABS System such as 2S/1M?

The “S” is a convention used to denote the sensors in an ABS system, while the “M” refers to the modulator valves. Describing an

ABS system as 2S/1M simply means that it uses 2 sensors and 1 modulator valve. The basic 2S/1M system is used to monitor two

sensors attached to each wheel end of one axle, which is controlled by one modulator valve that receives instructions from an

electronic brain called an ECU.

Why would one use a 4S/2M system on a trailer instead of the basic 2S/1M system?

The configuration of an ABS system typically depends upon the intended use of the trailer unit. While a 2S/1M system may meet the

minimum legal requirements, geographic road conditions can make a 4S/2M system more logical by offering added control of two

axles independently or side-by-side control of the trailer. Full type trailers require 4S/2M systems.

What makes tractor and trailer ABS systems different?

Many modern tractor ABS systems use 4S/4M systems, and others can be 6S, depending upon the number of sensors used and the

number of axles present on the tractor unit. Trailers, on the other hand, typically employ a 2S/1M system with sensors present on

only one axle.

How does a trailer ABS system function with two tanks?

Historically, two tanks have been used on trailers to protect pressures and ensure that the braking system would have charged air.

However, due to the modern 8x air volume requirement, a single jumbo tank could be used. The use of two tanks is still typically

used in applications where there are tight spaces, or a number of auxiliary devices are used.

On which axles should I install my ABS sensors?

ABS sensor location ultimately depends upon whether the trailer is equipped

with spring or air suspension. Typically, with spring suspension, sensors

should be installed in the axle furthest forward on the trailer, while with

air suspension, sensors should be installed to the rear axle in

double-axle units and the middle double-axle of triple double-axle units. The general

principal is to attach the sensors to the axle, or wheel ends,

that are most likely to lockup during a hard

braking event.

On which tank should I install my ABS valve?

As a general rule, valves should be installed centrally on a trailer. In other words, the tank that is closer to the center of the trailer in

terms of length of plumbing lines, should receive the valve. The reason for this is simply to ensure proper brake timing and balance.

ABS Basics - A Review

Need more information?

For more details regarding Haldex ABS

Systems, refer to L30041 ABS Manual or

Contact the Haldex Technical Services

Department at 800-643-2374.

L20555 US Rev 6/09 5M ALP

Haldex Limited

525 Southgate Drive, Unit 1

Guelph, Ontario CAN N1G 3W6

Phone: 519-826-7723

Fax: 519-826-9497

Haldex Brake Products Corporation

10930 N. Pomona Ave.

Kansas City, MO 64153-1256

Phone: 816-891-2470

Fax: 816-891-9447

www.haldex.com

Haldex Commercial Vehicle Systems

Haldex Part #

Package Contents

4725003000X

4725003010X

4725003020X

4725003200X

4725003210X

4725003220X

NOTE:

SKU #

Product Description

System Configuration

Connector Type

Remanufactured Truck/Tractor ABS

Reman Meritor Wabco Style

Screw-In

Connector

Type

Bayonet

Connector

Type

Modulcator V

alves

Complete F

ront Axle V

alve P

acks

Haldex Part #

Package Contents

V

alves

Haldex Part #

Package Contents

4725001000X

4725001010X

4725001020X

4725001030X

4725001200X

4725001210X

4725001220X

4725001230X

4725001240X

4725001250X

4725002030X

4725002220X

4725002230X

4725002240X

4725002250X

Complete Rear Axle V

alve P