Brake System Vehicle Road Test
Preliminary Inspections
1. |
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. |
3. |
Inspect the tire inflation
pressures and adjust as necessary. |
4. |
Inspect the tire tread
patterns to ensure that they are the same or very similar,
especially per axle. |
5. |
Ensure that the vehicle is not
loaded unevenly prior to brake system road testing. |
Road Testing Procedure
|
Warning:
Road test a vehicle under safe conditions and
while obeying all traffic laws. Do not attempt any maneuvers that
could jeopardize vehicle control. Failure to adhere to these
precautions could lead to serious personal injury and vehicle
damage. |
1. |
Start the engine and allow it
to idle. |
2. |
Check to see if the brake
system warning lamp remains illuminated. |
3. |
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 . |
4. |
Select a smooth, dry, clean
and level road or large lot that is as free of traffic and
obstacles as possible for brake system low speed road
testing. |
5. |
With the transmission in PARK,
lightly apply the brake pedal. Observe both the pedal feel and the
pedal travel. |
6. |
If the brake pedal apply felt
spongy, or the pedal travel was excessive, DO NOT drive the vehicle
until it is repaired. |
7. |
If the brake pedal apply did
not feel spongy and the pedal travel was not excessive, proceed to
step 8. |
8. |
Release and apply the
brakes. |
9. |
While continuing to apply the
brakes, shift the transmission into DRIVE, 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.
|
10. |
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.
|
11. |
If the brake pedal apply
effort was excessive, or the pedal travel was excessive, DO NOT
continue to test drive the vehicle until it is repaired.
|
12. |
If the brake pedal apply
effort was not excessive and the pedal travel was not excessive,
proceed to step 13. |
13. |
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
him. |
14. |
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. |
15. |
Select a smooth, dry, clean
and level road that is as free of heavy traffic as possible for
brake system moderate speed road testing. |
16. |
Drive the vehicle at a
moderate speed. Observe for a pull and/or incorrect tracking of the
vehicle without the brakes applied. |
17. |
While continuing to drive the
vehicle at a moderate speed, perform several light applies of the
brakes. Observe the pedal effort and the pedal travel, observe for
brake system noise, pulsation and/or brake drag. |
18. |
If the brake pedal apply
effort was excessive, or the pedal travel was excessive, DO NOT
continue to test drive the vehicle until it is repaired.
|
19. |
If the brake pedal apply
effort was not excessive and the pedal travel was not excessive,
proceed to step 20. |
20. |
While continuing to drive the
vehicle at a moderate speed, perform several moderate applies of
the brakes. Observe the pedal effort and the pedal travel, observe
for brake system pulsation and/or uneven braking action - either
side to side, or front to rear. |
|
A small amount of vehicle front end dip is expected during a
moderate apply of the brakes. |
21. |
If the brake pedal apply
effort was excessive, or the pedal travel was excessive, DO NOT
continue to test drive the vehicle until it is repaired.
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