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SECTION 4D

FRONT BRAKES

SPECIFICATIONS

General Specifications

Application
Value (s)
Front Brake Rotors
Diameter
296 mm
Thickness
29 mm
Discard Thickness
27.4
Leteral Runout (Installed)
0.04 mm
Brake Caliper Diameter
Front
45 mm + 45 mm (Dual)
Front Brake Pad
Thickness
10.5 mm
Discard Thickness
2 mm

Fastener Tightening Specifications

Application
N•m
Lb-Ft
Lb-In
Rotor Detent Screw
8
-
71
Brake Caliper Guide Pin Bolts
44
32
-
Brake Caliper Bracket Bolts
170
125
-
Brake Hose-to-Caliper Inlet Bolt
44
32
-

DIAGNOSIS

Brake Pad Inspection

  1. Raise and suitably support the vehicle.
  2. Remove the front wheels. Refer to Section 2E, Tiresand Wheels.
  3. Visually check the brake pads for minimumthickness and wear.
  4. Measure the thickness. Refer to "General Specifications" in this section.
  5. Install the brake shoes in axle sets only.
  6. Install the brake shoes in axle sets only.
  7. Install the front wheels. Refer to Section 2E, Tiresand Wheels.
  8. Lower the vehicle.

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Rotor Inspection

Brake rotors are manufactured with close tolerances for thickness variation, flatness, and lateral runout, but pits and grooves are created in rotors during usage. Lack of uniformity of the braking surfaces of the rotor can cause inadequate braking and a pulsating pedal during braking. The surface finish of the rotor is also important because an unsuitable surface finish can cause pulling and rapid wear of the brake shoe lining. If a rotor does not meet the specification, it should be refinished to specification or replaced. Refinishing of the rotor should only be done with precision equipment.
Thickness variation can be checked by measuring the thickness of the rotor at four or more points around the circumference of the rotor. All measurements must be made at the same distance from the edge of the rotor. A rotor that varies by more than. 1.0 mm (0.04 inch) can cause pedal pulsation and/or front end vibration during braking. Thickness can be measured with a commercially available micrometer and should be 27.4 mm (1.1 inch) or over.

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Light scoring of the rotor surfaces is acceptable if it does not exceed 0.40 mm (0.016 inch) in depth. Scoring measurements can be made with a commercially available brake micrometer.
Lateral runout cannot exceed 0.04 mm (0.001 inch). If lateral runout exceeds the specification, make sure that there is no dirt between the rotor and the hub and that hub-to-rotor contact surfaces are smooth and free from burrs. Use a commercially available dial indicator to check the lateral runout according to the following procedure:
  1. Position the transaxle in NEUTRAL and raise the vehicle.
  2. To preserve wheel balance, mark the relative positions of the wheel and hub, and remove the front wheel.
  3. Fasten the brake rotor to the wheel hub.
  4. Mount a dial indicator on the brake caliper.
  5. Place the indicator tip approximately 10 mm (0.39 inch) from the outer edge of the brake rotor, perpendicular to the disc and under slight preload. Observe the indicator gauge while rotating the rotor.
  6. After measuring is completed, remove the dial indicator and wheel nuts.
  7. If necessary, refinish the rotor with precision equipment. Measure the runout again after refinishing. If the runout exceeds 0.04 mm (0.001 inch) after refinishing, the rotor should be replaced.
  8. Align the marks that were made before wheel removal, and install the front wheel.
  9. Lower the vehicle.

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MAINTENANCE AND REPAIR

ON-VEHICLE SERVICE


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Brake Pads

Removal Procedure

  1. Raise and suitably support the vehicle. Refer to Section 0B, General Information.
  2. To preserve wheel balance, mark the position of thefront wheel relative to the wheel hub.
  3. Remove the front wheel. Refer to Section 2E, Tiresand Wheels.
  4. Remove the brake caliper lower guide pin bolt.

    5. Important : Caliper removal is not necessary to servicethe brake pads.

  5. Pivot the caliper upward and secure the caliper with heavy mechanics wire or equivalent.
  6. Remove the brake pads.

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Installation Procedure

  1. Install the brake pads.
  2. If new brake pads are being installed, they will bethicker than the worn pads that were removed. Pushthe caliper piston inward, if necessary.
  3. Install the brake caliper lower guide pin bolt.

    4. Important : Do not damage the piston dust seal whenthe caliper is pulled downward to reinstall the caliper lower guide pin bolt.

    Tighten
    Tighten the caliper lower guide pin bolt to 44 N•m (32 lb-ft).

  4. Align the marks that were made when removing thefront wheel, and install the wheel. Refer to Section2E, Tires and Wheels.

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Caliper

Removal Procedure

  1. Raise and suitably support the vehicle. Refer to Section 0B, General Information.
  2. To retain wheel balance, mark the position of the frontwheel relative to the wheel hub. Remove the wheel.Refer to Section2E, Tires and Wheels.
  3. Remove the caliper brake hose inlet bolt. Remove thering seals.
  4. To prevent fluid loss or contamination, plug openingsat the caliper inlet and the brake hose.
  5. Remove the caliper guide pin bolts.
  6. Remove the caliper.

    7. Notice : Support the brake caliper with heavy mechanic's wire, or equivalent, whenever it is separated from its mount and the hydraulic flexible brake hose is still connected. Failure to support the caliper in this manner will cause the flexible brake hose to bear the weight of the caliper, which may cause damage to the brake hose and in turn may cause a brake fluid leak.


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Installation Procedure

  1. Install the caliper guide pin bolts.

    2. Tighten
    Tighten the caliper guide pin bolts to 44 N•m (32 lb-ft).

  2. Install the brake hose to the caliper with the bolt andthe ring seals.

    3. Tighten
    Tighten the brake hose to caliper inlet bolt to 44 N•m(32 lb-ft).


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  3. Align the marks that were made when removing thefront wheel, and install the wheel. Refer to Section2E, Tires and Wheels.
  4. Lower the vehicle.
  5. Fill the master cylinder reservoir to the proper levelwith clean brake fluid.
  6. Bleed the air out of the brake system. Refer to Section4A, Hydraulic Brakes.

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Caliper Bracket

Removal Procedure

  1. Remove the caliper guide pin bolts, remove the caliper and pads.

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  2. Remove the caliper bracket bolts.

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Installation Procedure

  1. Install the caliper bracket bolts.

    2. Tighten
    Tighten the caliper bracket bolts to 170 N•m (125 lb-ft).


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  2. Install the brake pads and caliper.

    3. Tighten
    Tighten the caliper guide pin bolts to 44 N•m (32 lb-ft).


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Rotor

Removal Procedure

  1. Remove the caliper bracket. Refer to "Caliper Bracket" in this section.

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  2. Remove the rotor detent screw.
  3. Remove the rotor.

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Installation Procedure

    Important : To guarantee uniform braking, always refinishboth rotors even if only one rotor is defective.

  1. Install the rotor on the front wheel hub and install thedetent screw.

    2. Tighten
    Tighten the rotor detent screw to 8 N•m (71 lb-in).


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  2. Apply a few drops of thread-locking compound to thecaliper bracket bolts and install the caliperbracket.

    3. Tighten
    Tighten the caliper bracket bolts to 170 N•m(125 lb-ft).


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Splash Shield

Removal Procedure

  1. Remove the rotor. Refer to "Rotor"in this section.
  2. Remove the hub. Refer to

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  3. Remove the splash shield.

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Installation Procedure

  1. Install the splash shield.
  2. Secure the splash shield between the knuckle and hub assembly.
  3. Install the rotor. Refer to "Rotor" in this section.

GENERAL DESCRIPTIONAND SYSTEM OPERATION

Disc Brake Caliper

The caliper has dual bore and is mounted to the steering knuckle with two mounting bolts. Hydraulic pressure, created by applying the brake pedal, is converted by the caliper to a stopping force. This force acts equally against the piston and the bottom of the caliper bore to move the piston outward and to slide the caliper inward, resulting in a clamping action on the rotor. This clamping action forces the linings against the rotor, creating friction to stop the vehicle.


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