Pinpoint Tests

Pinpoint Tests

PINPOINT TEST G978762p1 : BRAKES NOISY

G978762t1 : INSPECT BRAKE PADS
1 Inspect the condition of the front and rear brake pads. Check for damage to any anti-squeal shims.
- Are the brake pads OK?

->Yes
GO to Pinpoint Test G978762t2.

->No
Clean/install new front and rear brake pads as required. For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Front Disc Brake Pads with Standard Brakes
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes Front Disc Brake Pads with High Performance Brakes
For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Rear Disc Brake Pads
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes
Re-test vehicle for brake noise.

G978762t2 : INSPECT BRAKE DISCS
1 Inspect the brake discs for excessive corrosion, wear or disc thickness variation.
- Does excessive corrosion, wear or disc thickness variation exist?

->Yes
Install new front and rear brake discs and brake pads as required. For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Front Disc Brake Pads with Standard Brakes
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes Front Disc Brake Pads with High Performance Brakes
For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Rear Disc Brake Pads
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes
For additional information, refer to Brake Disc - Vehicles With: Standard Brakes Front Disc Brake Disc with Standard Brakes
For additional information, refer to Brake Disc - Vehicles With: High Performance Brakes Front Disc Brake Disc with High Performance Brakes
For additional information, refer to Brake Disc - Vehicles With: Standard Brakes Rear Brake Disc
For additional information, refer to Brake Disc - Vehicles With: High Performance Brakes
Re-test vehicle for brake noise.

->No
No action required, vehicle is OK.

PINPOINT TEST G978762p2 : VIBRATION WHEN BRAKES ARE APPLIED

G978762t3 : ROAD TEST VEHICLE
1 Road test the vehicle between 40-80 km/h (25-50 mph) without applying brakes.
- Is the vibration present?

->Yes
For noise vibration and harshness tests. For additional information, refer to Noise, Vibration and Harshness (NVH).
->No
GO to Pinpoint Test G978762t4.

G978762t4 : CHECK FOR BRAKE VIBRATION
1 Road test the vehicle between 40-80 km/h (25-50 mph) with light and medium application on the brake pedal.
- Is a vibration present?

->Yes
Check the brake caliper mounting bolts and wheel hub nuts and tighten to specification as required. Check the balance of all road wheels and tires and repair as required. Check the brake discs for excessive wear, runout, thickness variation or cracks. Install new brake discs and brake pads as required.
GO to Pinpoint Test G978762t5.

->No
No action required, vehicle is OK.

G978762t5 : IS VIBRATION STILL PRESENT UNDER BRAKE APPLICATION?
1 Road test the vehicle between 40-80 km/h (25-50 mph) with light and medium application on the brake pedal.
- Is a vibration present?

->Yes
Check for wear or failure of steering gear bushings. Check for wear or failure of steering gear ball joints. Check for wear or failure of front wheel bearings, suspension bushings and ball joints. Check for wear or failure of rear wheel bearings, suspension bushings and ball joints. Refer to relevant section in this product and install new components as required.

->No
No action required, vehicle is OK.

PINPOINT TEST G978762p3 : THE BRAKES PULL OR DRIFT

G978762t6 : ROAD TEST VEHICLE
1 Road test the vehicle and apply the brake pedal.
- Does the vehicle pull or drift?

->Yes
GO to Pinpoint Test G978762t7.

->No
No action required, vehicle is OK.

G978762t7 : INSPECT TIRE CONDITION/PRESSURE
1 Check for excessive tire wear or incorrect pressures.
- Are the tires at the correct pressure and in good condition?

->Yes
GO to Pinpoint Test G978762t8.

->No
Adjust the tire pressures or install new tires if excessively worn. Re-test the system for normal operation.

G978762t8 : CHECK CALIPERS
1 Check the disc brake caliper pistons and pins for binding, leaking or sticking.
- Do the disc brake caliper pistons and pins bind, leak or stick?

->Yes
Rectify sticking pins and install new brake calipers as required. For additional information, refer to Brake Caliper - Vehicles With: Standard Brakes Front Disc Brake Caliper with Standard Brakes
For additional information, refer to Brake Caliper - Vehicles With: High Performance Brakes Front Disc Brake Caliper with High Performance Brakes
For additional information, refer to Brake Caliper - Vehicles With: Standard Brakes Rear Disc Brake Caliper
For additional information, refer to Brake Caliper - Vehicles With: High Performance Brakes.
Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t9.

G978762t9 : INSPECT BRAKE DISCS
1 Check the brake discs for excessive damage, thickness variation or runout. For additional information, refer to Brake Disc Runout Check Brake Disc Runout Check
- Does excessive damage or runout exist?

->Yes
Install new brake discs and brake pads as required. Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t10.

G978762t10 : INSPECT THE FRONT HUB AND WHEEL BEARING ASSEMBLY
1 Check the front hub and wheel bearing assembly.
- Are the wheel bearings OK?

->Yes
GO to Pinpoint Test G978762t11.

->No
Install new wheel bearings as required. For additional information, refer to Front Wheel Bearing and Wheel Hub Front Suspension Re-test the system for normal operation.

G978762t11 : CHECK SUSPENSION BUSHINGS AND BALL JOINTS.
1 Check all suspension bushings and ball joints.
- Are the suspension bushings and ball joints OK?

->Yes
GO to Pinpoint Test G978762t12.

->No
Install new front suspension bushings and ball joints as required. Install new rear suspension bushings and ball joints as required. Refer to the relevant section in this product.

G978762t12 : CHECK VEHICLE ALIGNMENT
1 Check the vehicle alignment.
For additional information, refer to Front Subframe - 4.2L Front Subframe
- Is the alignment within specification?

->Yes
No action is required, vehicle is OK.

->No
For additional information, refer to Front Subframe - 4.2L Front Subframe

PINPOINT TEST G978762p4 : THE PEDAL FEELS SPONGY

G978762t13 : CHECK FOR SPONGY PEDAL (ENGINE OFF)
1 Check for a firm brake pedal.
- Is the brake pedal effort and brake pedal travel normal?

->Yes
No action is required, vehicle is OK.

->No
GO to Pinpoint Test G978762t14.

G978762t14 : CHECK BRAKE PEDAL RESERVE (ENGINE OFF)
1 Pump the brake pedal 10 times and hold on the final application.
- Does the brake pedal feel firm on final application?

->Yes
GO to Pinpoint Test G978762t15.

->No
Bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair

G978762t15 : CHECK BRAKE PEDAL RESERVE (ENGINE ON)
1 With engine running at idle speed.
2 Apply the brake pedal lightly three or four times.
3 Wait 15 seconds for the vacuum to recover.
4 Push down on the brake pedal until it stops moving downward or an increased resistance to the brake pedal travel occurs.
5 Hold the brake pedal in the applied position while increasing the engine speed to 2000 revs/min.
6 Release the accelerator pedal.
- Does the brake pedal move downward as the engine speed returns to idle?

->Yes
GO to Pinpoint Test G978762t16.

->No
Check the vacuum to brake booster.

G978762t16 : CHECK BRAKE FLUID LEVEL
1 Check the brake master cylinder reservoir fluid level.
- Is the fluid level OK?

->Yes
Bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

->No
Check for leaking brake system and rectify as required. Add fluid and bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

PINPOINT TEST G978762p5 : THE PEDAL GOES DOWN FAST

G978762t17 : ROAD TEST VEHICLE
1 Road test the vehicle and apply the brake pedal.
- Is the brake pedal effort and brake pedal travel normal?

->Yes
No action required, vehicle is OK.

->No
GO to Pinpoint Test G978762t18.

G978762t18 : CHECK BRAKE PEDAL TRAVEL-PRESSURIZE SYSTEM
1 Pump the brake pedal rapidly (five times).
- Does the brake pedal travel build up and then hold?

->Yes
Bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t19.

G978762t19 : CHECK FOR BRAKE SYSTEM LEAKS
1 Check for external brake system leaks. For additional information, refer to brake master cylinder component tes.
- Is there a leak present?

->Yes
Repair as necessary, add fluid and bleed brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

->No
No action required, system is OK.

PINPOINT TEST G978762p6 : THE PEDAL GOES DOWN SLOWLY

G978762t20 : ROAD TEST VEHICLE - CHECK BRAKE PEDAL OPERATION
1 Check if the condition occurs during actual stopping application by applying the brake pedal while the vehicle is moving.
- Does the condition occur when the vehicle is moving?

->Yes
GO to Pinpoint Test G978762t21.

->No
GO to Pinpoint Test G978762t22.

G978762t21 : CHECK FOR BRAKE SYSTEM LEAKS
1 Check for external brake system leaks. For additional information, refer to brake master cylinder component test.
- Are there any external brake system leaks?

->Yes
Rectify as necessary. Add fluid and bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t22.

G978762t22 : CARRY OUT A BRAKE MASTER CYLINDER BYPASS TEST
1 Test for brake master cylinder bypass condition. Refer to Brake master cylinder component test.
- Has a concern been identified?

->Yes
Install a new brake master cylinder, add fluid and bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

->No
No action required, system is OK.

PINPOINT TEST G978762p7 : EXCESSIVE BRAKE PEDAL EFFORT

G978762t23 : CHECK BRAKE PADS
1 Check the brake pads for wear, contamination, correct installation, damage and type.
- Has a concern been identified?

->Yes
Correctly install or install new brake pads as required. For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Front Disc Brake Pads with Standard Brakes
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes Front Disc Brake Pads with High Performance Brakes
For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Rear Disc Brake Pads
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes
Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t24.

G978762t24 : CHECK VACUUM
1 Disconnect the vacuum hose from the brake booster.
2 Connect a vacuum/pressure tester to the vacuum hose.
3 Run the engine at normal operating temperature.
4 Record the vacuum reading.
- Is the reading 40.5 kPa (12 in-Hg) or greater?

->Yes
GO to Pinpoint Test G978762t25.

->No
Locate and rectify the source of low vacuum. Re-test the system for normal operation.

G978762t25 : INSPECT SYSTEM
1 Switch the engine off.
2 Reconnect the vacuum hose.
3 Inspect the brake booster, rubber grommet, and all vacuum plumbing for cracks, holes, damaged connections, or missing clamps.
4 Pump the brake pedal several times to exhaust the vacuum. Push down on the brake pedal and hold.
- Does the brake pedal move down when the engine is started?

->Yes
Vacuum system is OK.

->No
GO to Pinpoint Test G978762t26.

G978762t26 : CHECK POWER BRAKE BOOSTER VALVE
1 Check the brake booster valve. For additional information, refer to Brake Booster component test.
- Is the power brake booster valve OK?

->Yes
Check the brake booster. For additional information, refer to Brake Booster component test. Install a new brake booster as required. For additional information, refer to Brake Booster - LHD Service and Repair
For additional information, refer to Brake Booster - RHD
Re-test the system for normal operation.

->No
Install a new brake booster valve. Re-test the system for normal operation.

PINPOINT TEST G978762p8 : BRAKE LOCKUP DURING LIGHT BRAKE PEDAL FORCE

G978762t27 : TEST BRAKE LOCKUP
1 Road test the vehicle and apply the brake pedal lightly.
- Do the brakes lockup?

->Yes
GO to Pinpoint Test G978762t28.

->No
No action required, vehicle is OK.

G978762t28 : INSPECT BRAKE PADS
1 Inspect brake pads for contamination, correct installation, damage and type.
- Has a concern been identified?

->Yes
Correctly install or install new brake pads as required. For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Front Disc Brake Pads with Standard Brakes
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes Front Disc Brake Pads with High Performance Brakes
For additional information, refer to Brake Pads - Vehicles With: Standard Brakes Rear Disc Brake Pads
For additional information, refer to Brake Pads - Vehicles With: High Performance Brakes
Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t29.

G978762t29 : INSPECT BRAKE CALIPERS
1 Inspect brake calipers for binding, leaking or sticking.
- Has a concern been identified?

->Yes
Correctly install or install new brake calipers as required. For additional information, refer to Brake Caliper - Vehicles With: Standard Brakes Front Disc Brake Caliper with Standard Brakes
For additional information, refer to Brake Caliper - Vehicles With: High Performance Brakes Front Disc Brake Caliper with High Performance Brakes
For additional information, refer to Brake Caliper - Vehicles With: Standard Brakes Rear Disc Brake Caliper
For additional information, refer to Brake Caliper - Vehicles With: High Performance Brakes
Re-test the system for normal operation.

->No
No action required, vehicle is OK.

PINPOINT TEST G978762p9 : BRAKES DRAG

G978762t30 : ROAD TEST VEHICLE
1 Road test the vehicle and apply the brakes.
- Are the brakes functioning correctly?

->Yes
No action required, vehicle is OK.

->No
GO to Pinpoint Test G978762t31.

G978762t31 : CHECK BRAKE CALIPERS
1 Check the front and rear calipers pistons and pins for binding, leaking or sticking.
- Do the disc brake caliper pistons and pins bind, leak or stick?

->Yes
Inspect the brake calipers and parking brake cables. Install new components as required. Re-test the system for normal operation.

->No
GO to Pinpoint Test G978762t32.

G978762t32 : CHECK BRAKE BOOSTER
1 Check the brake booster connecting rod alignment and travel.
- Is the connecting rod OK?

->Yes
Vehicle is OK.

->No
Install a new brake booster as required. For additional information, refer to Brake Booster - LHD Service and Repair
For additional information, refer to Brake Booster - RHD
Re-test the system for normal operation.

PINPOINT TEST G978762p10 : EXCESSIVE/ERRATIC BRAKE PEDAL TRAVEL

G978762t33 : TEST ON ROUGH ROAD
1 Road test the vehicle on rough road conditions.
2 Apply the brakes slowly.
- Is the brake pedal effort and brake pedal travel normal?

->Yes
No action required, vehicle is OK.

->No
GO to Pinpoint Test G978762t34.

G978762t34 : CHECK BRAKE FLUID LEVEL
1 Check the brake master cylinder reservoir fluid level.
- Is the fluid level OK?

->Yes
GO to Pinpoint Test G978762t35.

->No
Check brake master cylinder reservoir sealing points. For additional information, refer to Brake master cylinder component test. Add brake fluid and bleed the brake system. For additional information, refer to Brake System Bleeding Service and Repair Re-test the system for normal operation.

G978762t35 : CHECK BRAKE PEDAL RESERVE
1 Run engine at idle speed.
2 Apply the brake pedal lightly three or four times.
3 Wait 15 seconds for the vacuum to replenish.
4 Push down on the brake pedal until it stops moving downward or an increased resistance to the brake pedal travel occurs.
5 Hold the brake pedal in the applied position while increasing the engine speed to 2000 revs/min.
6 Release the accelerator pedal.
- Does the brake pedal move downward as the engine speed returns to idle?

->Yes
GO to Pinpoint Test G978762t36.

->No
Check the vacuum to the brake booster.

G978762t36 : CHECK THE FRONT WHEEL BEARING ASSEMBLY
1 Check the front wheel bearing assembly.
- Are the front wheel bearings loose/damaged?

->Yes
Tighten to specification or install a new front wheel bearing as required. For additional information, refer to Front Wheel Bearing and Wheel Hub Front Suspension Re-test the system for normal operation.

->No
Check the front brake discs for thickness variances.

PINPOINT TEST G978762p11 : SLOW OR INCOMPLETE BRAKE PEDAL RETURN

G978762t37 : CHECK FOR BRAKE PEDAL RETURN
1 Run the engine at idle while making several brake applications.
2 Pull the brake pedal rearward with approximately 44.5 N (10lb) force.
3 Release the brake pedal and measure the distance to the toe board.
4 Make a hard brake application.
5 Release the brake pedal and measure the brake pedal to toe board distance. The brake pedal should return to its original position.
- Does the brake pedal return to its original position?

->Yes
No action required, vehicle is OK.

->No
GO to Pinpoint Test G978762t38.

G978762t38 : CHECK FOR BRAKE PEDAL BINDING
1 Disconnect the brake booster from the brake pedal. Check the brake pedal to ensure free operation.
- Is the brake pedal operating freely?

->Yes
Install a new brake booster as required. For additional information, refer to Brake Booster - LHD Service and Repair
For additional information, refer to Brake Booster - RHD
Re-test the system for normal operation.

->No
Repair or install new brake pedal. Re-test the system for normal operation.