Hummer H1 (2006+). Manual — part 245

7-62

Brake System

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Installation

1.

Install the brake line adapters in the same position as in the original modulator. Torque the 12 mm threaded adapter to 11 lb-ft
(15 N•m) and the 10 mm adapter to 9 lb-ft (12 N•m).

2.

Place the modulator alignment pin in the hole in the mounting bracket, install the two mount bolts and torque to 5 lb-ft (7
N•m).

3.

Connect the motor pump wire connector to the mounting bracket and install the assembly on the left air lift bracket with four
bolts, washers and lock washers. Torque the bolts to 28 lb-ft (38N•m).

4.

Connect the four wheel brake lines in their respective positions on the modulator and torque to 11 lb-ft (15 N•m).

5.

Connect the master cylinder hoses in their respective positions on the modulator and torque to 11 lb-ft (15 N•m).

6.

Connect the thirteen-pin, the two-pin and the one-pin wire connectors to the modulator assembly.

7.

Install the horn bracket and horns.

8.

Install the left front splash shield.

9.

Bleed the complete brake system.

10. Connect the batteries.

SPEED SENSOR REPLACEMENT

NOTE: The procedure for speed sensor replacement is basically the same for all four wheel ends.

WARNING: Connect speed sensors to the proper harness connectors. Connecting speed sensors to incorrect har-
ness connectors can cause the ABS/TT4 to malfunction.

Removal

1.

Rotate and pull the speed sensor head from the speed sensor mounting bracket and retaining sleeve (Figure 7-58).

2.

Remove and discard the speed sensor retaining sleeve.

Figure 7-58: Speed Sensor Removal

3.

Remove the speed sensor connector from the retaining clip near the top of the upper A-arm and disconnect the speed sensor
lead from the speed sensor harness (Figure 7-59).

4.

Remove the capscrews and clips securing the speed sensor lead to the A-arm and geared hub, and remove the sensor from the
vehicle.

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Brake System 7-63

5745804

Figure 7-59: Speed Sensor Connection

Installation

NOTE: The left side speed sensor leads route across above the halfshaft cv-joint. care must be taken to ensure that the lead does
not come in contact with the cv-joint.

1.

Clean all grease, rust and debris from the speed sensor cavity in the speed sensor mounting bracket.

Figure 7-60: Left Side Sensor Lead Routing

2.

Install a new speed sensor retainer sleeve in the speed sensor mounting bracket.

3.

Lubricate the head of the speed sensor with chassis lube and install in the speed sensor mounting bracket. Push the speed
sensor all the way in until it touches the tone wheel on the CV joint.

4.

Route the speed sensor lead away from the halfshaft and secure with the clips and capscrews (do not kink the speed sensor
lead).

CLIP

SENSOR

CONNECTOR

9-S07-015

P-CLAMP

P-CLAMP

SENSOR

LEAD

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7-64

Brake System

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5.

Connect the speed sensor connector to the speed sensor harness connector and install into the connector retaining clip.

TONE WHEEL REPLACEMENT

NOTE: The tone wheel is pressed onto the outer CV joint of the halfshaft and requires halfshaft replacement when servicing the
tone wheel. See section 9.

ABS ECU REPLACEMENT

1.

Turn ignition switch “OFF”.

2.

Remove the ECU enclosure hold-down bracket and lift the top half of the ECU enclosure up and out of the pocket in the
windshield washer fluid reservoir.

3.

Pull the ECU and ECU harness out of the lower half of the ECU enclosure, depress the lock tabs on the 35 pin harness
connector and swing the connector around until the hook on the end opposite of the lock tab disconnects from the ECU.

4.

Reverse the procedure for installation.

FUSE AND RELAY REPLACEMENT

The ABS TT4 system has two fuses located in the under-hood fuse/relay center (Figure 7-61):

1.

A 5 ampere ignition power fuse.

2.

A 40 ampere motor pump fuse.

The ABS TT4 system has four relays:

1.

Valve relay.

2.

Warning relay.

3.

Pump relay 1.

4.

Pump relay 2.

The valve relay and the warning relay are located in the under-hood fuse/relay center (Figure 7-61). The valve and warning relays
are accessible after removal of the under-hood fuse/relay center cover. The two pump relays are located forward of the fuse-relay
center and can be accessed after removing the ABS ECU enclosure hold-down bracket.

Figure 7-61: ABS/TT4 Relay Locations.

VALVE

RELAY

PUMP

RELAY 1

PUMP

RELAY 2

WARNING

RELAY

40 AMP
MOTOR

PUMP

20 AMP

IGNITION

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Brake System 7-65

5745804

ESSENTIAL TOOLS

Procure from Kent-Moore.

SPECIAL TOOLS

Tool No.

Description

J–35592

ABS Pinout Box

J–42553

Disc Brake Piston Retraction Tool

J–42883

Wheel Speed Sensor Test Cable

J–44237

ABS Blink Code Jumper

J–44238

Master Cylinder Bleed Adapter (not shown)

J–45405

Brake Line Flaring Kit (not shown)

J–45761

T-Handle Rachet Wrench (9/16") (not shown)

Tool No.

Description

J–29532-A

Diaphragm Brake Bleeder

8-S07-001

J–42553

9-S07-016

5

1 0

1 5

2 0

2 5

3 0

3 5

4

9

1 4

1 9

2 4

2 9

3 4

3

8

1 3

1 8

2 3

2 8

3 3

2

7

1 2

1 7

2 2

2 7

3 2

1

6

1 1

1 6

2 1

2 6

3 1

J 3

5 5

9 2

P I

N O

U T

B O

X

J–35592

00-S07-001

00-S07-002

J-44237

J-42883

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