Road Testing the Vehicle

1. Road Test the vehicle for the condition described by the customer. The initial test should be performed on a smooth highway, free of road crown, ruts, speed bumps, or pot holes.

^ Drive the vehicle at highway speeds, preferably without cross wind conditions.
^ If cross wind conditions are prevalent, drive the vehicle in both directions to the cross wind.
^ Decel the vehicle from highway speeds without applying the brakes.

Record any drift condition noticed.

^ Identify whether the vehicle drifts while holding the steering wheel or does it drift only after the steering wheel is allowed to move freely.

2. Next, perform several brake applications from speeds greater than 50 mph to a complete stop. This portion of the road test should be performed on several different types of road surfaces.

^ First series of brake applications should be a normal type of brake application (similar to the way you would come to a stop at a stop sign).
^ Second series of brake applications should be a hard braking application but, try not to activate the Anti lock Brake System (ABS).

Record what happens to the vehicle during each series of brake applications.

^ Does the vehicle drift to one side?
^ If it does, does the steering wheel move during the drift?
^ Did a wheel lock-up during a normal brake apply?

Then, if conditions permit, perform one stop allowing ABS to activate.

Record any individual wheels that may have locked-up.

Normal ABS operation will allow a wheel to intermittently lock-up. This intermittent lock-up is a controlled lock-up. If a wheel fully locks-up and does not release, then the ABS did not control the lock-up.

^ Did the drift condition differ during the one ABS stop?

NOTE:
IF THE VEHICLE IS EQUIPPED WITH REAR WHEEL ANTILOCK (RWAL) ONLY, THE ABS CONTROLS THE REAR WHEELS ONLY.

Continue driving the vehicle for five to ten minutes with limited braking if possible (allowing brakes to cool).

Repeat Step 2, brake drift evaluation.

Return to dealership, making several "snubs" along the way. These snubs are moderate brake applies from 50 mph to 30 mph, or 40 mph to 20 mph. The object is to retain the heat generated from braking in the brakes so brake drag measurements can be taken during the following brake evaluation.

3. If the vehicle did drift, perform the Brake System Evaluation test.