What this test is for
Capture the safest useful operating pattern and location evidence so braking diagnosis does not begin with an unsupported assumption about a rotor or another part.
Use the procedure to narrow a cause group. The result must be interpreted against the exact vehicle, equipment, and conditions.
- 01PurposeCapture the safest useful operating pattern and location evidence so braking diagnosis does not begin with an unsupporte
- 02PrepareSafe observation conditions / Inspection light
- 03MeasureCheck the stop-driving gate / Compare the trigger only when safe
- 04InterpretBraking safety takes priority; an unsafe vehicle should not be driven to reproduce a vibration.
- 05ContinueWheel/tire condition inspection / Brake-system inspection
Follow the sequence, stop when evidence changes the path, and verify the exact vehicle information before acting.
Preserve the operating conditions, equipment setup, and result before moving to the next branch.
Tools and preparation
- Safe observation conditions
- Inspection light
- Accurate tire-pressure gauge
- Approved lifting and support equipment
- Exact brake service information
Procedure and interpretation
Check the stop-driving gate
Record warning lamps, pedal feel, pull, smoke, leakage, heat, wheel security, and handling from a safe position before moving the vehicle.
No active safety condition requires stopping the test and arranging qualified inspection.
Braking safety takes priority; an unsafe vehicle should not be driven to reproduce a vibration.
Compare the trigger only when safe
Under normal, legal, low-risk conditions, note whether the same road-speed range is smooth with the brakes released and changes with gentle brake application. Do not perform repeated hard stops or hands-off steering.
The complaint can be classified as brake-applied, road-speed, mixed, or not safely comparable.
The trigger chooses the next system path; it does not identify a failed rotor, pad, tire, hub, or suspension component.
Record where the feedback is felt
Note pedal pulsation, steering-wheel movement, seat/body vibration, noise, pull, speed, brake effort, road surface, and recent wheel or brake work.
Location and operating conditions are preserved as evidence rather than treated as a parts diagnosis.
Feedback can travel through the vehicle, so the strongest location is a clue and not proof of the source.
Inspect and measure the complete wheel-end
With approved support and the exact vehicle procedure, inspect tires, wheels, mounting, hubs, friction material, hardware, calipers, hoses, and suspension; measure only with the specified method and limits.
The next measurement or repair addresses a documented condition across both sides where applicable.
A measurement outside a vehicle-specific limit supports the relevant branch, but a universal internet threshold is not a safe substitute for service information.
Record this test result
Save a bounded result and note to the selected vehicle. This is a personal record, not a verified diagnosis.
Choose a vehicle in My Garage or the vehicle selector first. IAR will not attach a test result to an unknown vehicle.
What to test next
Safety boundary
Braking and road-test safety
Do not create a road test if braking is reduced, the pedal feels unsafe, the vehicle pulls strongly, a red warning is on, there is smoke, leakage, severe heat, wheel looseness, or unstable handling. Use qualified inspection or transport instead.