External Conditions That Affect Brake Performance

Tires
Tires having unequal contact, and unequal grip on road surfaces will cause unequal braking. Tires must be equally inflated, and the tread pattern of right and left tires must be approximately equal.

Vehicle Loading
A heavily loaded vehicle requires more braking effort. When a vehicle has unequal loading, the most heavily loaded wheels require more braking power than the other wheels.

Wheel Alignment
Misalignment of the wheels, particularly excessive camber and caster, will cause the vehicle to steer to one side when the brakes are applied.

Brake Pedal Travel
^ Tools Required
- J 28662 Brake Pedal Effort Gauge and a Tape Measure
1. With the engine off and the key in the OFF position, pump the brake pedal until all vacuum reserve is exhausted from the power booster. A definite change in pedal feel occurs.
2. Install the J 28662 onto the brake pedal.
3. Hook end of tape measure over the top edge of the brake pedal and measure the distance to the rim of the steering wheel.
4. Apply brake pedal with 445 N (100 lb) force and re-measure.
5. Subtract the at rest measurement (step 3) from the applied measurement (step 4). The difference between the two pedal positions is the pedal travel.
6. The pedal travel should not exceed 57 mm (2.24 inch).
7. If the pedal travel is greater than the specification, refer to Brake System Diagnosis.

Brake Fluid Leak
With the engine running at idle and the shift lever in PARK (P), depress the brake pedal and hold a constant foot pressure on the pedal. If the pedal gradually falls away with the constant pressure, the hydraulic system may be leaking. Check the following parts visually to confirm a suspected leak:
^ Master Cylinder Fluid Levels. While a slight drop in the level occurs with normal lining wear, an abnormally low level, resulting in illumination of the BRAKE warning lamp, may mean a leak in the system. The system may be leaking internally or externally, refer to Master Cylinder Diagnosis.
^ Brake Hose and Pipe Connections. If leakage is found, verify torque of fasteners and/or replace the hose or pipe.
^ Connecting Brake Components. Inspect for damage, and rebuild or replace as needed.
^ Caliper. If leakage is found, rebuild or replace the assembly. Also check the service brake pedal, brake adjustment and parking brake adjustment.