Hummer H1 (2006+). Manual - part 235

7-22

Brake System

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Figure 7-16:   Hydro-Boost And Master Cylinder Mounting

Figure 7-17:   Service Brake Rotor 

REAR DUAL SERVICE/PARKING BRAKE PAD REPLACEMENT

Removal

1.

Put the transmission in PARK, chock the wheels, and release the parking brake.

2.

Remove the cotter pin, washer, and clevis pin securing the parking brake cable to the lever. Discard the cotter pin (Figure
 7-18).

3.

Remove the clip securing the parking brake cable to the caliper cable bracket and disconnect the cable from the caliper cable
bracket. Discard the clip.

CAUTION: The caliper must be supported during the removal to prevent damage to the brake line.

4.

Remove the two capscrews and washers securing the yoke and caliper to the adapter, and pull the yoke and caliper away from
the rotor (Figure  7-19).

NOTE: Note the positioning of the brake pad surfaces for installation.

5.

Remove the two brake pads from the adapter and rotor.

Cleaning and Inspection 

NOTE: Clean all components, examine for wear or damage, and replace if necessary.

 FRONT BRAKE LINE

HYDRO-

MASTER

REAR BRAKE LINE

BOOST

CYLINDER

HALFSHAFT

ROTOR

OUTPUT FLANGE

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 Brake System  7-23

5745804

1.

Clean the mating surfaces of the caliper, adapter, guide pins and sleeves.

Figure 7-18:   Rear Dual Brake Components

Figure 7-19:   Rear Dual Brake Pad and Rotor

2.

Inspect the caliper and caliper piston face for pitting or damage (Figure  7-20).

3.

Inspect the piston dust boot and bushings for tears or deterioration.

CALIPER CABLE

CLIP

PARKING BRAKE

CABLE

CLEVIS PIN

PARKING BRAKE 

LEVER

CLEVIS

BRACKET

COTTER

PIN

WASHER

ADAPTER

BRAKE PAD

ADAPTER SLIDE

YOKE

CALIPER

BRAKE PAD

ROTOR

TAPPED

HOLE

CAP

SCREW

7-24

Brake System

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4.

Inspect the caliper cable bracket for looseness, damage, and rotation.

5.

Thoroughly clean and inspect the rotor for heat checks, discoloration, pitting, or scoring (Figure  7-19).

CAUTION: Ensure that grease and oil are not in contact with the rotor and/or brake pad friction surface. Failure to do so will re-
sult in damage to equipment and poor performance.

NOTE: Replace the brake pads in sets only. If operation in wet and muddy conditions is expected, replace the brake pads if the
brake lining thickness is less than 1/8 in. (3.2 mm).

6.

Inspect the brake pads for glazing, oil saturation, or wear. If glazed, oil saturated, or if the brake lining thickness is less than 1/
8 in. (3.2 mm), replace both of the pads and the pads on opposite caliper.

Figure 7-20:   Rear Dual Brake Caliper 

Installation

WARNING:  Ensure the brake pads are installed with the linings facing the rotor. Failure to do this will cause poor
performance and damage to the equipment and may result in injury.

1.

Check the brake pad backing plate notches for burrs or excess coating and ensure that the pad will fit the adapter slide with 
enough clearance to afford stick-free movement.

CAUTION: Remove any excess lubricant that may have squeezed out from between mating surfaces. Do not allow any lubricant to
come in contact with the brake pad friction material or brake rotor surfaces.

2.

Lubricate the caliper guide pins, sleeves and adapter slides with Permatex

®

Ultra Disc Brake Caliper Lube prior to installation.

NOTE: Always apply thread-locking compound to the tapped holes. 

3.

Apply thread-locking compound to the tapped holes of adapter.

4.

Using special tool J–42553, rotate the caliper piston in a clockwise direction, and at the same time apply force on the outer
piston face until the caliper piston is seated in the piston bore (Figure  7-20).

5.

Position the caliper and the yoke on the adapter and rotor. Secure the yoke to the adapter with the two washers and capscrews.
Using a crowsfoot, tighten the capscrews to 40 lb-ft (54 N•m) (Figure  7-19).

6.

Install the parking brake cable to the caliper cable bracket and secure with the clip (Figure  7-21).

CALIPER CABLE BRACKET

CALIPER

DUST BOOT

CALIPER PISTON FACE

BUSHING

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 Brake System  7-25

5745804

Figure 7-21:   Rear Dual Brake Caliper Cable

CAUTION: Ensure the lever is in contact with the caliper cable bracket stop. Damage to the equipment and poor performance will
result if not aligned properly. Ensure that the clevis and clevis pin are aligned to the lever. Do not move the lever to accommodate
a maladjusted clevis. Damage to the equipment and poor performance will result.

7.

Install the parking brake clevis to the lever with the clevis pin, washer, and cotter pin. Check the position of the lever and
ensure it is in contact with the caliper cable bracket stop.

8.

Adjust the rear dual service/parking brake.

REAR DUAL SERVICE/PARKING BRAKE CALIPER REPLACEMENT

Removal

1.

Release the parking brake.

2.

Remove the cotter pin, washer, and clevis pin securing the parking brake clevis to the lever. Discard the cotter pin (Figure
 7-21).

3.

Remove the clip and parking brake cable from the caliper cable bracket. Discard the clip.

4.

Disconnect the brake line from the coupling (Figure  7-22).

5.

Remove the coupling and copper washer from the caliper.

CLIP

PARKING BRAKE

CABLE

CLEVIS PIN

PARKING BRAKE CLEVIS 

LEVER

CALIPER

CABLE BRACKET

CALIPER CABLE

BRACKET STOP