Operation CHARM: Car repair manuals for everyone.

Brake System Testing

Test the brakes on a dry, clean, reasonably smooth and level roadway.
A true braking test cannot be made if the roadway is wet, greasy or covered with loose dirt so that all tires do not grip the road equally.
Testing is adversely affected if the roadway is crowned, which would throw the weight of the vehicle toward the wheels on one side. Testing is also adversely affected if the roadway is so rough that the wheels tend to bounce.
Test the brakes at different vehicle speeds, with both light and heavy brake pedal pressure. If the vehicle is not equipped with an Antilock Brake System, avoid locking the brakes and sliding the tires. Locked brakes and sliding tires do not indicate brake efficiency, since heavily braked but turning wheels will stop a vehicle in less distance than locked wheels.
The brake system is balanced in order to avoid locking the wheels except at very high deceleration rates. Because of a high deceleration capability, a firmer brake pedal may be felt at higher deceleration levels.