Preliminary Inspections
- Visually inspect easily accessible brake system components for obvious
damage and/or leaks which may indicate that the vehicle should not be driven until
further inspections have been completed.
- Inspect the brake fluid level in the master cylinder reservoir and top
up only if necessary for brake system road testing. Refer to
Master Cylinder Reservoir Filling.
- Inspect the tyre inflation pressures and adjust as necessary.
- Inspect the tyre tread patterns to make sure that they are
the same or very similar, especially per axle.
- Make sure that the vehicle is not loaded unevenly prior to brake system
road testing.
Road Testing Procedure
Warning: Refer to Road Test Warning in the Preface section.
- Start the engine and allow it to idle.
- Visually inspect if the brake warning indicator remains illuminated.
- If the brake system warning lamp remains illuminated, DO NOT proceed to
test drive the vehicle until it is diagnosed and repaired. Refer to
Symptoms - Hydraulic Brakes.
- Select a smooth, dry, clean and level road or large allotment that is
as free of traffic and obstacles as possible for brake system low speed road testing.
- On a level surface, put the transmission in Park or Neutral and lightly
apply the brake pedal. Observe both the pedal feel and the pedal travel.
| • | If the brake pedal application felt spongy, or the pedal travel was greater
than desired, DO NOT drive the vehicle until it is repaired. |
| • | If the brake pedal application did not feel spongy and the pedal travel
was not greater than desired, proceed to step 6. |
- Release and apply the brakes.
- While continuing to apply the brakes, shift the transmission into DRIVE
or 1st, release the brakes and allow the engine to idle the vehicle away from the
stopped position. Observe for a slow release of the brake system.
- With the aid of an assistant to observe the vehicle's performance from
outside of the vehicle, drive the vehicle at a low speed and lightly apply the brakes
while driving past the assistant. Have the assistant observe for brake system noise
from the side of the vehicle closest to them, while you observe both the pedal effort
and the pedal travel.
| • | If the brake pedal application effort was greater than desired, or the
pedal travel was greater than desired, DO NOT continue to test drive the vehicle until
it is repaired. |
| • | If the brake pedal application effort was not greater than desired and
the pedal travel was not greater than desired, proceed to step 9. |
- Drive the vehicle in the opposite direction, at the same low speed and
lightly apply the brakes while driving past the assistant. Have the assistant observe
for brake system noise from the side of the vehicle closest to the assistant.
- Drive the vehicle at a low speed and shift the transmission into NEUTRAL
without applying the brakes. Observe for a rapid deceleration in vehicle speed, indicating
possible brake drag.
- Select a smooth, dry, clean and level road that is as free of heavy traffic
as possible for brake system moderate speed road testing.
- Drive the vehicle at a moderate speed. Observe for a pull and/or incorrect
tracking of the vehicle without the brakes applied.
- While continuing to drive the vehicle at a moderate speed, perform several
light brake applications. Observe the pedal effort and the pedal travel, observe for
brake system noise, pulsation and/or brake drag.
| • | If the brake pedal application effort was greater than desired, or the
pedal travel was greater than desired, DO NOT continue to test drive the vehicle until
it is repaired. |
| • | If the brake pedal application effort was not greater than desired and
the pedal travel was not greater than desired, proceed to step 14. |
- While continuing to drive the vehicle at a moderate speed, perform several
moderate brake applications. Observe the pedal effort and the pedal travel, observe
for brake system pulsation and/or uneven braking action [dash ] either side to side,
or front to rear.
A small amount of vehicle front end dip is expected
during a moderate brake application.
- If the brake pedal apply effort was greater than desired, or the pedal
travel was greater than desired, DO NOT continue to test drive the vehicle until it
is repaired.
